Q2.1:

What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?

A2.1:

Supported OS and software versions

The following tables detail the operating system and software package versions that are supported on IBM Storage Scale. Only the most recent versions of IBM Storage Scale releases are listed. If you need information about earlier versions, see Archived support information for IBM Storage Scale.

IBM Storage Scale is not supported on OS versions that are out of support by the OS vendor. Use the following tables for the supported versions:

Note:

• Before you implement any kernel changes, always check the FAQ section. Only update the kernel version when the version is explicitly listed in the FAQ as tested and supported. Kernel errata can be applied to the current kernel version unless they are explicitly listed in the FAQ as not supported. Always validate kernel changes including errata with IBM Storage Scale in a test environment before rolling out to production. Always rebuild the portability layer after any kernel changes.
• NIS authentication is not supported in RHEL 9.
• Dynatrace cannot be used on IBM Storage Scale on AIX due to built-in memory tracking. Unstable behavior including crashes will occur.

Interactive version: A dynamic table that lists the detailed support information for IBM Storage Scale releases is available at: https://public.dhe.ibm.com/storage/spectrumscale/support/.

This dynamic tool is still under development. The FAQ is the primary source of updated information.

Table 14. IBM Storage Scale 5.2.2.0: Tested software versions and latest tested kernels for Linux²

Architecture	RHEL1 8.8 8.10	RHEL1 9.24, 5, 9 9.4	Ubuntu 20.046, 7 20.04.5 20.04.6	Ubuntu 22.046, 7 22.04.4 22.04.5	SLES 15 SP5 SP6
x86_64	RHEL 8.8: 4.18.0-477.86.1.el8_8 RHEL 8.10: 4.18.0-553.34.1.el8_10 SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)	RHEL 9.2: 5.14.0-284.100.1.el9_2 RHEL 9.4 5.14.0-427.42.1.el9_4 SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)	Ubuntu 20.04: 5.4.0-147-generic Ubuntu 20.04.5: 5.4.0-139-generic Ubuntu 20.04.6: 5.4.0-204-generic SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)	Ubuntu 22.04: 5.15.0-27-generic Ubuntu 22.04.4: 5.15.0-122-generic Ubuntu 22.04.5: 5.15.0-122-generic SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)	SLES 15 SP5: 5.14.21-150500.55.88.1 SLES 15 SP6: 6.4.0-150600.23.33.1 SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)
Power LE	RHEL 8.8: 4.18.0-477.81.1.el8_8 RHEL 8.10: 4.18.0-553.27.1.el8_10 SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)	RHEL 9.2: 5.14.0-284.11.1.el9_2 RHEL 9.4 5.14.0-427.13.1 SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)	Ubuntu 20.04: 5.4.0-29-generic Ubuntu 20.04.5: 5.4.0-146-generic Ubuntu 20.04.6: 5.4.0-204-generic SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)		SLES 15 SP5: 5.14.21-150500.53-default SLES 15 SP6: 6.4.0-150600.21-default
Linux on Z3	RHEL 8.8: 4.18.0-477.21.1.el8_8 RHEL 8.10: 4.18.0-553.30.1.el8_10 SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)	RHEL 9.2: 5.14.0-284.30.1.el9_2 RHEL 9.4 5.14.0-427.31.1_el9_4 SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)	No plan to support.	No plan to support.	SLES 15 SP5: 5.14.21-150500.55.83.1 SLES 15 SP6: 6.4.0-150600.23.33.1 SMB: 4.19.8 3-2 NFS: 5.7 (ibm 027.00)
ARM 648	No plan to support.	RHEL 9.4 5.14.0-427.13.1.el9_4.aarch64 5.14.0-427.16.1.el9_4.aarch64	No plan to support.	Ubuntu 22.04.x 5.15.0-97-generic linux-signatures-nvidia-6.2.0-1015-nvidia linux-signatures-nvidia-6.2.0-1015-nvidia-64k	No plan to support.

Table 15. IBM Storage Scale 5.2.2.0: Tested software versions and latest tested kernels for Windows and AIX

AIX 7.2	AIX 7.3	Windows 10 (>= version 1809, OS Build 17763)	Windows 11 (>= OS Build 22000)	Windows Server 2019 (>= version 1809, OS Build 17763)	Windows Server 2022 (>= OS Build 20348)
TL 5	TL 0
	TL 1
	TL 2 7300-02-01-2346

1. Red Hat® live kernel patching is not supported on IBM Storage Scale.
2. If protocols and authentication are enabled, python3-ldap needs to be installed for mmadquery to run.
3. With IBM Storage Scale 5.2.x, NFS and SMB protocols can be served from RHEL or SLES 15 on Linux on System Z servers. An RPQ would be required for IBM to review any requests for Integrated Protocol Server support. Ask your sales representative to contact IBM Storage Scale development about the RPQ or SCORE process.
4. Leap upgrade from RHEL 8 to 9 with IBM Storage Scale installed is not supported.
5. For RHEL 9, openssh-server-8.7p1-10.el9 or later is required (RHBA-2022:6598 - Bug Fix Advisory ).
6. Only the Ubuntu Server edition is supported.
7. Only the default, non-rolling generic kernel image for the Ubuntu Server edition is supported. Ubuntu Hardware Enablement (Ubuntu HWE) kernels and others are not supported with IBM Storage Scale.
8. The following page size kernels are supported for Advanced RISC Machine (ARM) architectures:
   • 4k and 64k for RHEL 9
   • Ubuntu 4k or 64k for Ubuntu 22.04.x
   • Nvidia 4k or 64k for Ubuntu 22.04.x

Table 16. IBM Storage Scale 5.2.1.1: Tested software versions and latest tested kernels for Linux²

Architecture	RHEL1 8.8 8.10	RHEL1 9.24, 5, 9 9.4	Ubuntu 20.046, 7 20.04.5 20.04.6	Ubuntu 22.046, 7 22.04.4 22.04.5	SLES 15 SP5 SP6
x86_64	RHEL 8.8: 4.18.0-477.86.1.el8_8 RHEL 8.10: 4.18.0-553.36.1.el8_10 SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)	RHEL 9.2: 5.14.0-284.100.1.el9_2 RHEL 9.4 5.14.0-427.42.1.el9_4 SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)	Ubuntu 20.04: 5.4.0-147-generic Ubuntu 20.04.5: 5.4.0-139-generic Ubuntu 20.04.6: 5.4.0-204-generic SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)	Ubuntu 22.04: 5.15.0-27-generic Ubuntu 22.04.4: 5.15.0-122-generic Ubuntu 22.04.5: 5.15.0-130-generic SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)	SLES 15 SP5: 5.14.21-150500.55.88.1 SLES 15 SP6: 6.4.0-150600.21-default SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)
Power LE	RHEL 8.8: 4.18.0-477.86.1.el8_8 RHEL 8.10: 4.18.0-553.27.1.el8_10 SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)	RHEL 9.2: 5.14.0-284.11.1.el9_2 RHEL 9.4 5.14.0-427.13.1 SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)	Ubuntu 20.04: 5.4.0-29-generic Ubuntu 20.04.5: 5.4.0-146-generic Ubuntu 20.04.6: 5.4.0-204-generic SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)		SLES 15 SP5: 5.14.21-150500.53-default SLES 15 SP6: 6.4.0-150600.21-default
Linux on Z3	RHEL 8.8: 4.18.0-477.21.1.el8_8 RHEL 8.10: 4.18.0-553.36.1.el8_10 SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)	RHEL 9.2: 5.14.0-284.30.1.el9_2 RHEL 9.4 5.14.0-427.31.1_el9_4 SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)	No plan to support.	No plan to support.	SLES 15 SP5: 5.14.21-150500.55.83.1 SLES 15 SP6: 6.4.0-150600.21-default SMB: 4.19.8 3-1 NFS: 5.7 (ibm 023.00)
ARM 648	No plan to support.	RHEL 9.4 5.14.0-427.13.1.el9_4.aarch64 5.14.0-427.16.1.el9_4.aarch64	No plan to support.	Ubuntu 22.04.x 5.15.0-97-generic linux-signatures-nvidia-6.2.0-1015-nvidia linux-signatures-nvidia-6.2.0-1015-nvidia-64k	No plan to support.

Table 17. IBM Storage Scale 5.2.1.1: Tested software versions and latest tested kernels for Windows and AIX

AIX 7.2	AIX 7.3	Windows 10 (>= version 1809, OS Build 17763)	Windows 11 (>= OS Build 22000)	Windows Server 2019 (>= version 1809, OS Build 17763)	Windows Server 2022 (>= OS Build 20348)
TL 5	TL 0
	TL 1
	TL 2 7300-02-01-2346

1. Red Hat live kernel patching is not supported on IBM Storage Scale.
2. If protocols and authentication are enabled, python3-ldap needs to be installed for mmadquery to run.
3. With IBM Storage Scale 5.2.x, NFS and SMB protocols can be served from RHEL or SLES 15 on Linux on System Z servers. An RPQ would be required for IBM to review any requests for Integrated Protocol Server support. Ask your sales representative to contact IBM Storage Scale development about the RPQ or SCORE process.
4. Leap upgrade from RHEL 8 to 9 with IBM Storage Scale installed is not supported.
5. For RHEL 9, openssh-server-8.7p1-10.el9 or later is required (RHBA-2022:6598 - Bug Fix Advisory ).
6. Only the Ubuntu Server edition is supported.
7. Only the default, non-rolling generic kernel image for the Ubuntu Server edition is supported. Ubuntu Hardware Enablement (Ubuntu HWE) kernels and others are not supported with IBM Storage Scale.
8. The following page size kernels are supported for Advanced RISC Machine (ARM) architectures:
   • 4k and 64k for RHEL 9
   • Ubuntu 4k or 64k for Ubuntu 22.04.x
   • Nvidia 4k or 64k for Ubuntu 22.04.x

Table 18. IBM Storage Scale 5.2.1.0: Tested software versions and latest tested kernels for Linux²

Architecture	RHEL1 8.8 8.9 8.10	RHEL1 9.24, 5, 9 9.4	Ubuntu 20.046, 7 20.04.5 20.04.6	Ubuntu 22.046, 7 22.04.2 22.04.3 22.04.4	SLES 15 SP5
x86_64	RHEL 8.8: 4.18.0-477.75.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.22.1.el8_10 SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)	RHEL 9.2: 5.14.0-284.88.1.el9_2 RHEL 9.4 5.14.0-427.42.1.el9_4 SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)	Ubuntu 20.04: 5.4.0-147-generic Ubuntu 20.04.5: 5.4.0-139-generic Ubuntu 20.04.6: 5.4.0-200-generic SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)	Ubuntu 22.04: 5.15.0-27-generic Ubuntu 22.04.2: 5.15.0-78-generic Ubuntu 22.04.3: 5.15.0-94-generic Ubuntu 22.04.4: 5.15.0-118-generic SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)	SLES 15 SP5: 5.14.21-150500.55.68.1 SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)
Power LE	RHEL 8.8: 4.18.0-477.75.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.22.1.el8_10 SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)	RHEL 9.2: 5.14.0-284.11.1.el9_2 RHEL 9.4 5.14.0-427.13.1 SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)	Ubuntu 20.04: 5.4.0-29-generic Ubuntu 20.04.5: 5.4.0-146-generic Ubuntu 20.04.6: 5.4.0-200-generic SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)		SLES 15 SP5: 5.14.21-150500.53-default
Linux on Z3	RHEL 8.8: 4.18.0-477.21.1.el8_8 RHEL 8.9: 4.18.0-513.18.1.el8_9 RHEL 8.10: 4.18.0-553.22.1.el8_10 SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)	RHEL 9.2: 5.14.0-284.30.1.el9_2 RHEL 9.4 5.14.0-427.31.1_el9_4 SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)	No plan to support.	No plan to support.	SLES 15 SP5: 5.14.21-150500.55.80.2 SMB: 4.19.7 3-2 NFS: 5.7 (ibm 022.00)
ARM 648	No plan to support.	RHEL 9.4 5.14.0-427.13.1.el9_4.aarch64 5.14.0-427.16.1.el9_4.aarch64	No plan to support.	Ubuntu 22.04.x 5.15.0-97-generic linux-signatures-nvidia-6.2.0-1015-nvidia linux-signatures-nvidia-6.2.0-1015-nvidia-64k	No plan to support.

Table 19. IBM Storage Scale 5.2.1.0: Tested software versions and latest tested kernels for Windows and AIX

AIX 7.2	AIX 7.3	Windows 10 (>= version 1809, OS Build 17763)	Windows 11 (>= OS Build 22000)	Windows Server 2019 (>= version 1809, OS Build 17763)	Windows Server 2022 (>= OS Build 20348)
TL 5	TL 0
	TL 1
	TL 2 7300-02-01-2346

1. Red Hat live kernel patching is not supported on IBM Storage Scale.
2. If protocols and authentication are enabled, python3-ldap needs to be installed for mmadquery to run.
3. With IBM Storage Scale 5.2.x, NFS and SMB protocols can be served from RHEL or SLES 15 on Linux on System Z servers. An RPQ would be required for IBM to review any requests for Integrated Protocol Server support. Ask your sales representative to contact IBM Storage Scale development about the RPQ or SCORE process.
4. Leap upgrade from RHEL 8 to 9 with IBM Storage Scale installed is not supported.
5. For RHEL 9, openssh-server-8.7p1-10.el9 or later is required (RHBA-2022:6598 - Bug Fix Advisory ).
6. Only the Ubuntu Server edition is supported.
7. Only the default, non-rolling generic kernel image for the Ubuntu Server edition is supported. Ubuntu Hardware Enablement (Ubuntu HWE) kernels and others are not supported with IBM Storage Scale.
8. The following page size kernels are supported for Advanced RISC Machine (ARM) architectures:
   • 4k and 64k for RHEL 9
   • Ubuntu 4k or 64k for Ubuntu 22.04.x
   • Nvidia 4k or 64k for Ubuntu 22.04.x

Table 20. IBM Storage Scale 5.2.0.1: Tested software versions and latest tested kernels for Linux²

Architecture	RHEL1 8.8 8.9 8.10	RHEL1 9.24, 5, 9 9.3 9.4	Ubuntu 20.046, 7 20.04.5 20.04.6	Ubuntu 22.046, 7 22.04.2 22.04.3 22.04.4	SLES 15 SP5
x86_64	RHEL 8.8: 4.18.0-477.70.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.16.1.el8_10 SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)	RHEL 9.2: 5.14.0-284.85.1.el9_2 RHEL 9.3 5.14.0-362.24.1.el9_3 RHEL 9.4 5.14.0-427.31.1.el9_4 SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)	Ubuntu 20.04: 5.4.0-147-generic Ubuntu 20.04.5: 5.4.0-139-generic Ubuntu 20.04.6: 5.4.0-195-generic SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)	Ubuntu 22.04: 5.15.0-27-generic Ubuntu 22.04.2: 5.15.0-78-generic Ubuntu 22.04.3: 5.15.0-94-generic Ubuntu 22.04.4: 5.15.0-118-generic SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)	SLES 15 SP5: 5.14.21-150500.55.73.1 SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)
Power LE	RHEL 8.8: 4.18.0-477.74.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.22.1.el8_10 SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)	RHEL 9.2: 5.14.0-284.11.1.el9_2 RHEL 9.3 5.14.0-362.8.1 RHEL 9.4 5.14.0-427.13.1 SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)	Ubuntu 20.04: 5.4.0-29-generic Ubuntu 20.04.5: 5.4.0-146-generic Ubuntu 20.04.6: 5.4.0-190-generic SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)		SLES 15 SP5: 5.14.21-150500.53-default
Linux on Z3	RHEL 8.8: 4.18.0-477.21.1.el8_8 RHEL 8.9: 4.18.0-513.18.1.el8_9 RHEL 8.10: 4.18.0-553.16.1.el8_10 SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)	RHEL 9.2: 5.14.0-284.30.1.el9_2 RHEL 9.3 5.14.0-362.8.1 RHEL 9.4 5.14.0-427.35.1.el9_4 SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)	No plan to support.	No plan to support.	SLES 15 SP5: 5.14.21-150500.55.73.1 SMB: 4.17.12 5-1 NFS: 5.7 (ibm 019.00)
ARM 648	No plan to support.	RHEL 9.3 5.14.0-362.18.1.el9_3.aarch64 5.14.0-362.18.1.el9_3.aarch64+64k RHEL 9.4 5.14.0-427.13.1.el9_4.aarch64 5.14.0-427.16.1.el9_4.aarch64	No plan to support.	Ubuntu 22.04.x 5.15.0-97-generic linux-signatures-nvidia-6.2.0-1015-nvidia linux-signatures-nvidia-6.2.0-1015-nvidia-64k	No plan to support.

Table 21. IBM Storage Scale 5.2.0.1: Tested software versions and latest tested kernels for Windows and AIX

AIX 7.2	AIX 7.3	Windows 10 (>= version 1809, OS Build 17763)	Windows 11 (>= OS Build 22000)	Windows Server 2019 (>= version 1809, OS Build 17763)	Windows Server 2022 (>= OS Build 20348)
TL 5	TL 0
	TL 1
	TL 2 7300-02-01-2346

1. Red Hat live kernel patching is not supported on IBM Storage Scale.
2. If protocols and authentication are enabled, python3-ldap needs to be installed for mmadquery to run.
3. With IBM Storage Scale 5.2.x, NFS and SMB protocols can be served from RHEL or SLES 15 on Linux on System Z servers. An RPQ would be required for IBM to review any requests for Integrated Protocol Server support. Ask your sales representative to contact IBM Storage Scale development about the RPQ or SCORE process.
4. Leap upgrade from RHEL 8 to 9 with IBM Storage Scale installed is not supported.
5. For RHEL 9, openssh-server-8.7p1-10.el9 or later is required (RHBA-2022:6598 - Bug Fix Advisory ).
6. Only the Ubuntu Server edition is supported.
7. Only the default, non-rolling generic kernel image for the Ubuntu Server edition is supported. Ubuntu Hardware Enablement (Ubuntu HWE) kernels and others are not supported with IBM Storage Scale.
8. The following page size kernels are supported for Advanced RISC Machine (ARM) architectures:
   • 4k and 64k for RHEL 9
   • Ubuntu 4k or 64k for Ubuntu 22.04.x
   • Nvidia 4k or 64k for Ubuntu 22.04.x
9. On RHEL 9.2, if you are using an IBM Storage Scale version that is previous to 5.1.9.4 or 5.2.0.1 and you updated to the 5.14.0-284.66.1 kernel, consult these IBM Support recommendations and workarounds to solve the struct_stat error.

Table 22. IBM Storage Scale 5.2.0: Tested software versions and latest tested kernels for Linux²

Architecture	RHEL1 8.6 8.8 8.9	RHEL1 9.04, 5 9.29 9.3	Ubuntu 20.046, 7 20.04.5 20.04.6	Ubuntu 22.046, 7 22.04.2 22.04.3 22.04.4	SLES 15 SP5
x86_64	RHEL 8.6: 4.18.0-372.98.1.el8_6 RHEL 8.8: 4.18.0-477.51.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)	RHEL 9.0: 5.14.0-70.93.2.el9_0 RHEL 9.2: 5.14.0-284.59.1.el9_2 RHEL 9.3 5.14.0-362.24.1.el9_3 SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)	Ubuntu 20.04: 5.4.0-147-generic Ubuntu 20.04.5: 5.4.0-139-generic Ubuntu 20.04.6: 5.4.0-174-generic SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)	Ubuntu 22.04: 5.15.0-27-generic Ubuntu 22.04.2: 5.15.0-78-generic Ubuntu 22.04.3: 5.15.0-94-generic Ubuntu 22.04.4: 5.15.0-97-generic SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)	SLES 15 SP5: 5.14.21-150500.55.52.1 SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)
Power LE	RHEL 8.6: 4.18.0-372.64.1.el8_6 RHEL 8.8: 4.18.0-477.67.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)	RHEL 9.0: 5.14.0-70.36.1.el9_0 RHEL 9.2: 5.14.0-284.11.1.el9_2 RHEL 9.3 5.14.0-362.8.1 SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)	Ubuntu 20.04: 5.4.0-29-generic Ubuntu 20.04.5: 5.4.0-146-generic Ubuntu 20.04.6: 5.4.0-174-generic SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)		SLES 15 SP5: 5.14.21-150500.53-default
Linux on Z3	RHEL 8.6: 4.18.0-372 RHEL 8.8: 4.18.0-477.21.1.el8_8 RHEL 8.9: 4.18.0-513.18.1.el8_9 SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)	RHEL 9.0: 5.14.0-284.18.1.el9_2 RHEL 9.2: 5.14.0-284.30.1.el9_2 RHEL 9.3 5.14.0-362.8.1 SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)	No plan to support.	No plan to support.	SLES 15 SP5: 5.14.21-150500.55.44.1 SMB: 4.17.12 4-1 NFS: 5.7 (ibm 017.00)
ARM 648	No plan to support.	RHEL 9.3 5.14.0-362.18.1.el9_3.aarch64+64k 5.14.0-362.18.1.el9_3.aarch64	No plan to support.	Ubuntu 22.04.x 5.15.0-97-generic linux-signatures-nvidia-6.2.0-1015-nvidia linux-signatures-nvidia-6.2.0-1015-nvidia-64k	No plan to support.

Table 23. IBM Storage Scale 5.2.0: Tested software versions and latest tested kernels for Windows and AIX

AIX 7.2	AIX 7.3	Windows 10 (>= version 1809, OS Build 17763)	Windows 11 (>= OS Build 22000)	Windows Server 2019 (>= version 1809, OS Build 17763)	Windows Server 2022 (>= OS Build 20348)
TL 5	TL 0
	TL 1
	TL 2 7300-02-01-2346

1. Red Hat live kernel patching is not supported on IBM Storage Scale.
2. If protocols and authentication are enabled, python3-ldap needs to be installed for mmadquery to run.
3. With IBM Storage Scale 5.2.x, NFS and SMB protocols can be served from RHEL or SLES 15 on Linux on System Z servers. An RPQ would be required for IBM to review any requests for Integrated Protocol Server support. Ask your sales representative to contact IBM Storage Scale development about the RPQ or SCORE process.
4. Leap upgrade from RHEL 8 to 9 with IBM Storage Scale installed is not supported.
5. For RHEL 9, openssh-server-8.7p1-10.el9 or later is required (RHBA-2022:6598 - Bug Fix Advisory ).
6. Only the Ubuntu Server edition is supported.
7. Only the default, non-rolling generic kernel image for the Ubuntu Server edition is supported. Ubuntu Hardware Enablement (Ubuntu HWE) kernels and others are not supported with IBM Storage Scale.
8. The following page size kernels are supported for Advanced RISC Machine (ARM) architectures:
   • 4k and 64k for RHEL 9
   • Ubuntu 4k or 64k for Ubuntu 22.04.x
   • Nvidia 4k or 64k for Ubuntu 22.04.x
9. On RHEL 9.2, if you are using an IBM Storage Scale version that is previous to 5.1.9.4 or 5.2.0.1 and you updated to the 5.14.0-284.66.1 kernel, consult these IBM Support recommendations and workarounds to solve the struct_stat error.

Table 24. IBM Storage Scale 5.1.9.7: Tested software versions and latest tested kernels for Linux²

Architecture	RHEL1 8.8 8.9 8.10	RHEL1 9.24, 5, 8 9.4	Ubuntu 20.046, 7 20.04.5 20.04.6	Ubuntu 22.046, 7 22.04.4 22.04.5	SLES 15 SP5 SP6
x86_64	RHEL 8.8: 4.18.0-477.86.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.34.1.el8_10 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)	RHEL 9.2: 5.14.0-284.100.1.el9_2 RHEL 9.4 5.14.0-427.42.1.el9_4 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)	Ubuntu 20.04.5: 5.4.0-139-generic Ubuntu 20.04.6: 5.4.0-204-generic SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)	Ubuntu 22.04.4: 5.15.0-118-generic Ubuntu 22.04.5: 5.15.0-122-generic SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)	SLES 15 SP5: 5.14.21-150500.55.88.1 SLES 15 SP6: 6.4.0-150600.21-default SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)
Power LE	RHEL 8.8: 4.18.0-477.83.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.22.1.el8_10 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)	RHEL 9.2: 5.14.0-284.11.1.el9_2 RHEL 9.4 5.14.0-427.13.1 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)	Ubuntu 20.04.5: 5.4.0-146-generic Ubuntu 20.04.6: 5.4.0-204-generic SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)		SLES 15 SP5: 5.14.21-150500.53-default SLES 15 SP6: 6.4.0-150600.21-default
Linux on Z3	RHEL 8.8: 4.18.0-477.21.1.el8_8 RHEL 8.9: 4.18.0-513.18.1.el8_9 RHEL 8.10: 4.18.0-553.33.1.el8_10 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)	RHEL 9.2: 5.14.0-284.30.1.el9_2 RHEL 9.4 5.14.0-427.31.1.el9_4 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)	No plan to support.	No plan to support.	SLES 15 SP5: 5.14.21-150500.55.80.2 SLES 15 SP6: 6.4.0-150600.21-default SMB: 4.17.12 6-1 NFS: 5.7 (ibm 027.00)

Table 25. IBM Storage Scale 5.1.9.7: Tested software versions and latest tested kernels for Windows and AIX

AIX 7.2	AIX 7.3	Windows 10 (>= version 1809, OS Build 17763)	Windows 11 (>= OS Build 22000)	Windows Server 2019 (>= version 1809, OS Build 17763)	Windows Server 2022 (>= OS Build 20348)
TL 4	TL 0
TL 5	TL 1
	TL 2 7300-02-01-2346

1. Red Hat live kernel patching is not supported on IBM Storage Scale.
2. If protocols and authentication are enabled, python3-ldap needs to be installed for mmadquery to run.
3. With IBM Storage Scale 5.1.x, NFS and SMB protocols can be served from RHEL or SLES 15 on Linux on System Z servers. An RPQ would be required for IBM to review any requests for Integrated Protocol Server support. Ask your sales representative to contact IBM Storage Scale development about the RPQ or SCORE process.
4. Leap upgrade from RHEL 8 to 9 with IBM Storage Scale installed is not supported.
5. For RHEL 9, openssh-server-8.7p1-10.el9 or later is required (RHBA-2022:6598 - Bug Fix Advisory ).
6. Only the Ubuntu Server edition is supported.
7. Only the default, non-rolling generic kernel image for the Ubuntu Server edition is supported. Ubuntu Hardware Enablement (Ubuntu HWE) kernels and others are not supported with IBM Storage Scale.

Table 26. IBM Storage Scale 5.1.9.6: Tested software versions and latest tested kernels for Linux²

Architecture	RHEL1 8.8 8.9 8.10	RHEL1 9.24, 5, 8 9.4	Ubuntu 20.046, 7 20.04.5 20.04.6	Ubuntu 22.046, 7 22.04.3 22.04.4	SLES 15 SP5 SP6
x86_64	RHEL 8.8: 4.18.0-477.75.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.27.1.el8_10 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)	RHEL 9.2: 5.14.0-284.88.1.el9_2 RHEL 9.4 5.14.0-427.42.1.el9_4 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)	Ubuntu 20.04.5: 5.4.0-139-generic Ubuntu 20.04.6: 5.4.0-200-generic SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)	Ubuntu 22.04.3: 5.15.0-94-generic Ubuntu 22.04.4: 5.15.0-118-generic SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)	SLES 15 SP5: 5.14.21-150500.55.73.1 SLES 15 SP6: 6.4.0-150600.21-default SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)
Power LE	RHEL 8.8: 4.18.0-477.75.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.22.1.el8_10 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)	RHEL 9.2: 5.14.0-284.11.1.el9_2 RHEL 9.4 5.14.0-427.13.1 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)	Ubuntu 20.04.5: 5.4.0-146-generic Ubuntu 20.04.6: 5.4.0-200-generic SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)		SLES 15 SP5: 5.14.21-150500.53-default SLES 15 SP6: 6.4.0-150600.21-default
Linux on Z3	RHEL 8.8: 4.18.0-477.21.1.el8_8 RHEL 8.9: 4.18.0-513.18.1.el8_9 RHEL 8.10: 4.18.0-553.27.1.el8_10 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)	RHEL 9.2: 5.14.0-284.30.1.el9_2 RHEL 9.4 5.14.0-427.31.1.el9_4 SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)	No plan to support.	No plan to support.	SLES 15 SP5: 5.14.21-150500.55.80.2 SLES 15 SP6: 6.4.0-150600.21-default SMB: 4.17.12 6-1 NFS: 5.7 (ibm 023.00)

Table 27. IBM Storage Scale 5.1.9.6: Tested software versions and latest tested kernels for Windows and AIX

AIX 7.2	AIX 7.3	Windows 10 (>= version 1809, OS Build 17763)	Windows 11 (>= OS Build 22000)	Windows Server 2019 (>= version 1809, OS Build 17763)	Windows Server 2022 (>= OS Build 20348)
TL 4	TL 0
TL 5	TL 1
	TL 2 7300-02-01-2346

1. Red Hat live kernel patching is not supported on IBM Storage Scale.
2. If protocols and authentication are enabled, python3-ldap needs to be installed for mmadquery to run.
3. With IBM Storage Scale 5.1.x, NFS and SMB protocols can be served from RHEL or SLES 15 on Linux on System Z servers. An RPQ would be required for IBM to review any requests for Integrated Protocol Server support. Ask your sales representative to contact IBM Storage Scale development about the RPQ or SCORE process.
4. Leap upgrade from RHEL 8 to 9 with IBM Storage Scale installed is not supported.
5. For RHEL 9, openssh-server-8.7p1-10.el9 or later is required (RHBA-2022:6598 - Bug Fix Advisory ).
6. Only the Ubuntu Server edition is supported.
7. Only the default, non-rolling generic kernel image for the Ubuntu Server edition is supported. Ubuntu Hardware Enablement (Ubuntu HWE) kernels and others are not supported with IBM Storage Scale.

Table 28. IBM Storage Scale 5.1.9.5: Tested software versions and latest tested kernels for Linux²

Architecture	RHEL1 7.9	RHEL1 8.8 8.9 8.10	RHEL1 9.24, 5, 8 9.3 9.4	Ubuntu 20.046, 7 20.04.5 20.04.6	Ubuntu 22.046, 7 22.04.2 22.04.3 22.04.4	SLES 15 SP5
x86_64	RHEL 7.9: 3.10.0-1160.119.1.el7 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 8.8: 4.18.0-477.55.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.16.1.el8_10 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 9.2: 5.14.0-284.82.1.el9_2 RHEL 9.3 5.14.0-362.24.1.el9_3 RHEL 9.4 5.14.0-427.35.1.el9_4 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	Ubuntu 20.04: 5.4.0-147-generic Ubuntu 20.04.5: 5.4.0-139-generic Ubuntu 20.04.6: 5.4.0-195-generic SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	Ubuntu 22.04: 5.15.0-27-generic Ubuntu 22.04.2: 5.15.0-78-generic Ubuntu 22.04.3: 5.15.0-94-generic Ubuntu 22.04.4: 5.15.0-118-generic SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	SLES 15 SP5: 5.14.21-150500.55.73.1 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)
Power LE	RHEL 7.9: 3.10.0-1160.119.1.el7 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 8.8: 4.18.0-477.55.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.16.1.el8_10 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 9.2: 5.14.0-284.11.1.el9_2 RHEL 9.3 5.14.0-362.8.1 RHEL 9.4 5.14.0-427.13.1 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	Ubuntu 20.04: 5.4.0-29-generic Ubuntu 20.04.5: 5.4.0-146-generic Ubuntu 20.04.6: 5.4.0-195-generic SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)		SLES 15 SP5: 5.14.21-150500.53-default
Linux on Z3	RHEL 7.9: 3.10.0-1160.102.1.el7 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 8.8: 4.18.0-477.21.1.el8_8 RHEL 8.9: 4.18.0-513.18.1.el8_9 RHEL 8.10: 4.18.0-553.16.1.el8_10 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 9.2: 5.14.0-284.30.1.el9_2 RHEL 9.3 5.14.0-362.8.1 RHEL 9.4 5.14.0-427.31.1.el9_4 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	No plan to support.	No plan to support.	SLES 15 SP5: 5.14.21-150500.55.65.1 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)

Table 29. IBM Storage Scale 5.1.9.5: Tested software versions and latest tested kernels for Windows and AIX

AIX 7.2	AIX 7.3	Windows 10 (>= version 1809, OS Build 17763)	Windows 11 (>= OS Build 22000)	Windows Server 2019 (>= version 1809, OS Build 17763)	Windows Server 2022 (>= OS Build 20348)
TL 4	TL 0
TL 5	TL 1
	TL 2 7300-02-01-2346

1. Red Hat live kernel patching is not supported on IBM Storage Scale.
2. If protocols and authentication are enabled, python3-ldap needs to be installed for mmadquery to run.
3. With IBM Storage Scale 5.1.x, NFS and SMB protocols can be served from RHEL or SLES 15 on Linux on System Z servers. An RPQ would be required for IBM to review any requests for Integrated Protocol Server support. Ask your sales representative to contact IBM Storage Scale development about the RPQ or SCORE process.
4. Leap upgrade from RHEL 8 to 9 with IBM Storage Scale installed is not supported.
5. For RHEL 9, openssh-server-8.7p1-10.el9 or later is required (RHBA-2022:6598 - Bug Fix Advisory ).
6. Only the Ubuntu Server edition is supported.
7. Only the default, non-rolling generic kernel image for the Ubuntu Server edition is supported. Ubuntu Hardware Enablement (Ubuntu HWE) kernels and others are not supported with IBM Storage Scale.

Table 30. IBM Storage Scale 5.1.9.4: Tested software versions and latest tested kernels for Linux²

Architecture	RHEL1 7.9	RHEL1 8.8 8.9 8.10	RHEL1 9.24, 5, 8 9.3 9.4	Ubuntu 20.046, 7 20.04.5 20.04.6	Ubuntu 22.046, 7 22.04.2 22.04.3 22.04.4	SLES 15 SP5
x86_64	RHEL 7.9: 3.10.0-1160.119.1.el7 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 8.8: 4.18.0-477.55.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.16.1.el8_10 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 9.2: 5.14.0-284.82.1.el9_2 RHEL 9.3 5.14.0-362.24.1.el9_3 RHEL 9.4 5.14.0-427.35.1.el9_4 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	Ubuntu 20.04: 5.4.0-147-generic Ubuntu 20.04.5: 5.4.0-139-generic Ubuntu 20.04.6: 5.4.0-195-generic SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	Ubuntu 22.04: 5.15.0-27-generic Ubuntu 22.04.2: 5.15.0-78-generic Ubuntu 22.04.3: 5.15.0-94-generic Ubuntu 22.04.4: 5.15.0-118-generic SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	SLES 15 SP5: 5.14.21-150500.55.73.1 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)
Power LE	RHEL 7.9: 3.10.0-1160.119.1.el7 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 8.8: 4.18.0-477.55.1.el8_8 RHEL 8.9: 4.18.0-513.24.1.el8_9 RHEL 8.10: 4.18.0-553.16.1.el8_10 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 9.2: 5.14.0-284.11.1.el9_2 RHEL 9.3 5.14.0-362.8.1 RHEL 9.4 5.14.0-427.13.1 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	Ubuntu 20.04: 5.4.0-29-generic Ubuntu 20.04.5: 5.4.0-146-generic Ubuntu 20.04.6: 5.4.0-195-generic SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)		SLES 15 SP5: 5.14.21-150500.53-default
Linux on Z3	RHEL 7.9: 3.10.0-1160.102.1.el7 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 8.8: 4.18.0-477.21.1.el8_8 RHEL 8.9: 4.18.0-513.18.1.el8_9 RHEL 8.10: 4.18.0-553.16.1.el8_10 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	RHEL 9.2: 5.14.0-284.30.1.el9_2 RHEL 9.3 5.14.0-362.8.1 RHEL 9.4 5.14.0-427.31.1.el9_4 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)	No plan to support.	No plan to support.	SLES 15 SP5: 5.14.21-150500.55.65.1 SMB: 4.17.12 5-1 NFS: 4.3 (ibm 073.16)

Table 31. IBM Storage Scale 5.1.9.4: Tested software versions and latest tested kernels for Windows and AIX

AIX 7.2	AIX 7.3	Windows 10 (>= version 1809, OS Build 17763)	Windows 11 (>= OS Build 22000)	Windows Server 2019 (>= version 1809, OS Build 17763)	Windows Server 2022 (>= OS Build 20348)
TL 4	TL 0
TL 5	TL 1
	TL 2 7300-02-01-2346

1. Red Hat live kernel patching is not supported on IBM Storage Scale.
2. If protocols and authentication are enabled, python3-ldap needs to be installed for mmadquery to run.
3. With IBM Storage Scale 5.1.x, NFS and SMB protocols can be served from RHEL or SLES 15 on Linux on System Z servers. An RPQ would be required for IBM to review any requests for Integrated Protocol Server support. Ask your sales representative to contact IBM Storage Scale development about the RPQ or SCORE process.
4. Leap upgrade from RHEL 8 to 9 with IBM Storage Scale installed is not supported.
5. For RHEL 9, openssh-server-8.7p1-10.el9 or later is required (RHBA-2022:6598 - Bug Fix Advisory ).
6. Only the Ubuntu Server edition is supported.
7. Only the default, non-rolling generic kernel image for the Ubuntu Server edition is supported. Ubuntu Hardware Enablement (Ubuntu HWE) kernels and others are not supported with IBM Storage Scale.
8. On RHEL 9.2, if you are using an IBM Storage Scale version that is previous to 5.1.9.4 or 5.2.0.1 and you updated to the 5.14.0-284.66.1 kernel, consult these IBM Support recommendations and workarounds to solve the struct_stat error.

Q2.2:

What is the IBM Storage Scale support position regarding clone Linux distributions (CentOS, Rocky Linux, Oracle Linux RHCK, ROCKS, White box Linux, etc.) ?

A2.2:

There are many Linux distributions out there. It would not be practical to try to test and support them all. The IBM Storage Scale team focuses on testing Enterprise Linux distributions RHEL, SLES and Ubuntu. However, there are some popular distributions in the Linux community that are created by essentially building the code from source packages corresponding to one of the enterprise distributions, usually with some cosmetic changes. IBM Storage Scale code may be able to work correctly on such a distribution, since it very closely resembles a supported one. However, we do not test IBM Storage Scale explicitly on such clone distributions, and will not be able to provide support for any problems specific to the use of the latter. If a problem is reported in such an environment, we will investigate it, but if the problem is suspected to be related to the type of distribution used, we may request that the problem be recreated on a supported distribution. Note that other IBM products may have a different support policy. We recommend that a supported distribution is used on NSD servers and other nodes that have SAN connectivity, to make it possible to get support with storage-related issues.

Note: IBM Storage Scale for Linux on Z is only supported on the distributions and kernel levels as documented in the question 2.1 What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?

Q2.3:

What are the current restrictions on IBM Storage Scale Linux kernel support?

A2.3:

Current restrictions on IBM Storage Scale Linux kernel support include:

• Any 5-level paging capable processors (for example, Ice Lake) need to apply a fix or disable 5-level paging in the OS. For more information, see IBM Spectrum Scale: Spectrum Scale requires a fix to run on the latest generation of Intel x86_64 hardware with 5-level page tables.
• For IBM Storage Scale on RHEL 7 or SLES 12 SP1 (kernel versions later than 3.7) to run on the Broadwell processors, the IBM Storage Scale version needs to be at version 4.1.1.10 or later on the 4.1 release and version 4.2.1.1 or later on the 4.2 release. On IBM Storage Scale releases earlier than version 4.1.1.10 on the 4.1 release and earlier than version 4.2.1.1 on the 4.2 release, it is necessary to follow the steps outlined below:
  • Disable the Supervisor Mode Access Prevention (smap) kernel parameter
  • Reboot the node before using GPFS
  • For more information, see http://www-01.ibm.com/support/docview.wss?uid=ssg1S1009287.
• Systemd is replacing traditional sysVinit in many Linux distributions. Though systemd should still support traditional sysVinit without any changes, starting with systemd version 219-19, this support is not working properly, causing IBM Storage Scale services not to startup at boot time. If you are experiencing this problem, you can do one of the following:
  • Upgrade your nodes to IBM Storage Scale V4.2.0.1.

    IBM Storage Scale uses systemd to start IBM Storage Scale services starting with V4.2.0.1.

  • Apply the following workaround:

    rm /etc/init.d/gpfs
    cp /usr/lpp/mmfs/bin/gpfsrunlevel /etc/init.d/gpfs

  • If systemd is upgraded to version 219 after IBM Storage Scale V4.2.0.1 was already installed, you can apply the workaround in the second option or take the following step to enable IBM Storage Scale services to use systemd:

    systemctl enable /usr/lpp/mmfs/lib/systemd/gpfs.service

Please also see the questions:

• What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?
• Is IBM Storage Scale on Linux supported in a virtualization environment?
• What are the current advisories for all platforms supported by IBM Storage Scale?
• What are the current advisories for IBM Storage Scale on Linux?

Q2.4:

What Linux distributions are supported by the integrated protocols access methods in IBM Storage Scale V4.1.1 and later?

A2.4:

For more information about which Linux distributions are supported by the integrated protocols access methods in IBM Storage Scale, see 2.1 What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?.

Two NFS services cannot run at the same time. You will need to stop and mask the Linux kernel nfs-server that is shipped with the distribution in order to use the NFS-Ganesha server that is shipped with IBM Storage Scale.

For NFS:

Because the IBM Storage Scale version of the NFS server must be used, the NFS service must be run with the mmces command instead of systemctl/service.

1. Determine if the nfs-server is available on any CES node by running the command mmdsh -N cesnodes systemctl status nfs-server. If any of the nodes report that the service is not masked, you will need to stop and mask the nfs-server:
   • mmdsh -N cesNodes systemctl stop nfs-server
   • mmdsh -N cesNodes systemctl mask nfs-server
2. You can then restart the IBM Storage Scale NFS service:
   • mmces service start nfs -a

For Swift Object:

You will need to reload the spectrum-scale-object-selinux module if the CES nodes are in SELinux Enforcing mode. To check whether they are in SELinux Enforcing mode, run the command: mmdsh -N cesnodes getenforce. If the mode is returned as Enforcing or Permissive, then run the following commands:

• mmces service stop obj -a
• mmdsh -N cesNodes semodule -i /usr/share/selinux/packages/spectrum-scale-object-selinux.pp
• mmces service start obj -a

Note: Also, see the question 15.6 What are the current advisories for IBM Storage Scale on Linux?

Q2.5:

What is the impact on the /dev, /proc/mounts, /etc/mtab directories and the mount command for IBM Storage Scale for Linux due to the recent changes in systemd? What happened to the block device in /dev? Why is the /dev/ prefix missing from the output of the mount command and also from /proc/mounts and /etc/mtab?

A2.5:

Starting with IBM Storage Scale 4.2.1, GPFS on Linux no longer creates a block device in /dev for the corresponding GPFS file system. As the result, the prefix /dev/ does not appear before the GPFS device name in the output of the Linux mount command and in files /etc/fstab , /etc/mtab, and /proc/mounts. On the other hand, commands that accept /dev/file-system-name as input will continue doing so. A few commands will still display the file system name as /dev/file-system-name.

For example:

c13c1apv7:~ # awk '$3 == "gpfs" { print }' /proc/mounts
/gpfs/automountdir/fs2 /gpfs/automountdir/fs2 gpfs rw,relatime 0 0
fs1 /gpfs/fs1 gpfs rw,relatime 0 0
fs5mpathd /fs5mpathd/a/few/level/mount/point gpfs rw,relatime 0 0
remote /remote gpfs rw,relatime 0 0
/gpfs/automountdir/fs3mpathb /gpfs/automountdir/fs3mpathb gpfs rw,relatime 0 0
/fs4mpathc /gpfs/automountdir/fs4mpathc gpfs rw,relatime 0 0
/gpfs/automountdir/autofs1 /gpfs/automountdir/autofs1 gpfs rw,relatime 0 0
/autofs2 /gpfs/automountdir/autofs2 gpfs rw,relatime 0 0
/autofs3 /gpfs/automountdir/autofs3 gpfs rw,relatime 0 0

c13c1apv7:~ # mount | awk '/type gpfs/ { print }'
/gpfs/automountdir/fs2 on /gpfs/automountdir/fs2 type gpfs (rw,relatime)
fs1 on /gpfs/fs1 type gpfs (rw,relatime)
fs5mpathd on /fs5mpathd/a/few/level/mount/point type gpfs (rw,relatime)
remote on /remote type gpfs (rw,relatime)
/gpfs/automountdir/fs3mpathb on /gpfs/automountdir/fs3mpathb type gpfs (rw,relatime)
/fs4mpathc on /gpfs/automountdir/fs4mpathc type gpfs (rw,relatime)
/gpfs/automountdir/autofs1 on /gpfs/automountdir/autofs1 type gpfs (rw,relatime)
/autofs2 on /gpfs/automountdir/autofs2 type gpfs (rw,relatime)
/autofs3 on /gpfs/automountdir/autofs3 type gpfs (rw,relatime)

Q2.6:

What are the limitations of IBM Storage Scale support for Windows ?

A2.6:

• GPFS for Windows supports most of the GPFS features that are available on AIX and Linux. Exceptions include certain GPFS commands to apply policies, administer quotas and administer ACLs, among others. These commands are thus unsupported in a Windows-only cluster. In a mixed (heterogeneous) cluster, these Windows-lacking commands can still be executed on Unix nodes without participation from the Windows nodes in that cluster.

  For more information, see the GPFS limitations on Windows topic in the IBM Storage Scale: Concepts, Planning, and Installation Guide.

  For more information about GPFS features that are not supported on Windows nodes, see 2.1 What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?.

Other limitations include:

• Exporting IBM Storage Scale file systems as Server Message Block (SMB) shares (also known as CIFS shares) from IBM Storage Scale Windows nodes is not supported.
• NFS serving (any version of NFS) by GPFS Windows nodes is not supported.
• IBM Storage Scale for Windows is not supported in any environment where Citrix Provisioning Services are deployed.
• Desktop editions of Windows (such as Windows 10 and Windows 11) do not support direct attached disks and can only operate as NSD clients. Windows Server editions support direct attached disks and can operate as NSD servers.
• In a mixed cluster, it is recommended that most GPFS administrative commands be executed on non-Windows nodes.
• The only supported way to achieve Windows-Unix user-mapping between Windows and Unix compute nodes is via RFC 2307 attributes. These attributes can be administered via Identity Mapping for Unix (IMU) from Microsoft in Windows Server versions up to and including Windows Server 2012 R2. Beginning with Windows Server 2016, these RFC 2307 attributes can be specified via the Active Directory Users and Computers (ADUC) MMC Snap-in as follows: From Administrative Tools, launch Active Directory Users and Computers (ADUC). Under View, enable Advanced Features. Next, navigate to the desired User object under Users. Open Properties. Under Attribute Editor tab, edit uidNumber, gidNumber, primaryGroupID, loginShell, unixHomeDirectory, and so on.IBM Storage Scale primarily uses the uidNumber and gidNumber attributes for user-mapping.
• In IBM Storage Scale V4 and later, the following user commands require Administrative privileges. They can only be run by a user who is a member of the Administrators group: mmchfileset, mmcrsnapshot, mmdelsnapshot, mmdf, mmlsdisk, mmlsfileset, mmlsfs, mmlspolicy, mmlspool, mmlssnapshot, and mmsnapdir.

• Encryption is not supported on Windows. The encryption function in the Advanced Edition should be disabled if Windows nodes are present in the cluster.
• IPv4 subnets are not supported in a cluster that is defined with IPv6 primary addresses (hostname) that contains Windows nodes.

• For TSM V7.1.1, which is only supported with IBM Storage Scale V4.1, see:
  • IBM Tivoli® Storage Manager V7.1.1 Knowledge Center at http://www-01.ibm.com/support/knowledgecenter/SSGSG7_7.1.1/com.ibm.itsm.tsm.doc/welcome.html.
  • TSM support page at https://www-947.ibm.com/support/entry/myportal/product/tivoli/tivoli_storage_manager?productContext=-2105539168.

For more information, see the following questions:

• What are the requirements for the use of OpenSSH on Windows nodes?
• Is IBM Storage Scale on Windows supported in a virtualization environment?

Q2.7:

What are the requirements for the use of OpenSSH on Windows nodes?

A2.7:

IBM Storage Scale requires the use of OpenSSH to support its administrative functions when the cluster includes Windows nodes and UNIX nodes. Install the Cygwin OpenSSH package as described in the Installing IBM Storage Scale on Windows nodes chapter of the IBM Storage Scale: Concepts, Planning, and Installation Guide. If you are using an OpenSSH package from another vendor, make sure that it is compatible with the Cygwin namespace and environment.

OpenSSH 9.0 includes a change that is incompatible with IBM Storage Scale. Ensure that OpenSSH 9.0 is not used with IBM Storage Scale. Earlier OpenSSH packages from Cygwin work. It is expected that this issue will be resolved with OpenSSH 9.1.

Q2.8:

Can different IBM Storage Scale maintenance levels coexist?

A2.8:

Different releases of IBM Storage Scale can coexist, that is, be active in the same cluster and simultaneously access the same file system. For release co-existence, IBM Storage Scale follows the N-1 rule. According to this rule, a particular IBM Storage Scale release (N) can co-exist with the prior release of IBM Storage Scale (N-1). This allows IBM Storage Scale to support an online (rolling) upgrade, that is a node by node upgrade. As expected, any given release of IBM Storage Scale can coexist with the same release. To clarify, the term release here refers to an IBM Storage Scale release stream and the release streams are currently defined as 4.2.x > 5.0.x > 5.1.x > 5.2.x.

These coexistence rules also apply for remote cluster access (multi-cluster remote mount). A node running release N-2 cannot perform a remote mount from a cluster which has nodes running release N, and vice versa.

Q2.9:

Are there any requirements for Clustered NFS (CNFS) support in IBM Storage Scale?

A2.9:

IBM Storage Scale supports Clustered NFS (CNFS) on SLES12 (see Archived support information for IBM Storage Scale in the FAQ) and RHEL levels supported by your version of IBM Storage Scale (see What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows? in the FAQ). However, there are limitations:

• Exporting using NFS V4 is supported starting with IBM Storage Scale V4.1 or later.
• CNFS over IPV6 is only supported with IBM Storage Scale V4.1 or later.
• It is very important to make all the nodes in the same group as identical as possible - from the hardware and software running on them to the configuration of IBM Storage Scale, NFS, and the network.
• CNFS is not supported on the Ubuntu distribution.
• CNFS is not supported on SLES 15 and later versions.
• CNFS is not able to export a remotely mounted filesystem.

Q2.10:

Does IBM Storage Scale support NFS V4?

A2.10:

Note: NFSv4 can be supported in the following ways:

• Clustered NFS
• Integrated protocols (CES and NFS), which support NFSv3, NFSv4.0 and NFSv4.1.
  Note: Some features of NFSv4.1 are not supported. For example, pNFS.

Enhancements to the support of Network File System (NFS) V4 are available on:

• AIX V6.1 or AIX V7.1.
• The following Linux distributions:
  • RHEL 5.5 and later, 6.x, and 7x.
  • SLES 11 SP1 and later, and SLES 12

Restrictions include:

• To support NFsv4 ACLs, the package nfs4-acl-tools must be installed.
• Windows-based NFSv4 clients are not supported with Linux/NFSv4 servers because of their use of share modes.
• If a file system is to be exported through CNFS (the Linux kernel NFSserver), then it must be configured to support POSIX ACLs (with -k all or -k posix option). This is because NFSv4/Linux servers will only handle ACLs properly if they are stored in GPFS as posix ACLs. On the other hand, if a file system is to be exported through CES (Using Samba and NFS Ganesha), then it must be configured to only support NFSv4 ACLs (with -k nfs4). This is because the CES stack has only been qualified with NFSv4 ACLs.
• Starting with Linux kernel version 2.6, an fsid value must be specified for each GPFS file system that is exported on NFS. For example, the format of the entry in /etc/exports for the GPFS directory /gpfs/dir1 might look like this:

  /gpfs/dir1 cluster1(rw,fsid=745)

  For further details see the Linux export considerations at Linux export considerations
• Concurrent AIX/NFSv4 servers, Samba servers and GPFS Windows nodes in the cluster are allowed. NFSv4 ACLs may be stored in GPFS filesystems via Samba exports, NFSv4/AIX servers, GPFS Windows nodes, ACL commands of Linux NFSv3 and ACL commands of GPFS. However, clients of Linux v4 servers will not be able to see these ACLs, just the permission from the mode.

For more information on the support of NFS V4, see the IBM Storage Scale documentation updates file at

• For IBM Storage Scale V4.1.1 and later, at http://www.ibm.com/support/knowledgecenter/STXKQY/ibmspectrumscale_welcome.html
• For GPFS V3.5 and V4.1, at http://www-01.ibm.com/support/knowledgecenter/SSFKCN/gpfs_welcome.html

Q2.11:

Are there any considerations for the use of the persistent reservation (PR) support in IBM Storage Scale?

A2.11:

Considerations for the use of Persistent Reserve include:

• Starting with IBM Storage Scale 5.2.1.0, NVMe reservations are supported only for multi-attach volumes in AWS virtual machines. For more information, see NVMe reservations in AWS documentation.
• Support for Persistent Reserve requires:
  • For V3.5 support on AIX V6.1 requires APAR IZ57224

    AIX 6.1 TL7 + Service Pack 4 is required to support Persistent Reserve without SDDPCM.

  • For V3.5 , V4.1 or V4.2 support on AIX V7.1, refer to the storage documentation to install the correct multipath driver.
• The use of Persistent Reserve is supported on GPFS tie-breaker disks with GPFS V3.5.0.21, or later, and IBM Storage Scale V4.1.0.4, or later.
  Note: See the question What are the current requirements/limitations for using the Cluster Configuration Repository (CCR) ?
• For the Activate Persist Through Power Loss (APTPL) feature:
  • On Linux, if the storage is capable of supporting APTPL, GPFS V3.5.0.15, or later supports this feature.
• Starting with 3.5.0.16, it is possible to have a descOnly disk that resides on a device that does not support SCSI-3 Persistent Reserve while allowing Persistent Reserve to be used on other disks in the same file system. The lack of Persistent Reserve support for the descOnly disk will not result in fast failover being disabled.

Also see the question What devices does GPFS support with SCSI-3 Persistent Reservations?

Q2.12:

What are the requirements/limitations for using native encryption in IBM Storage Scale Advanced Edition or Data Management Edition?

A2.12:

Considerations for the use of native encryption (encryption of data at rest on GPFS disks) in IBM Storage Scale Advanced Edition include:

• For each node that acts as a key server, the installation and use of either of the following key servers is required.
  • IBM Security Key Lifecycle Manager (ISKLM) V2.6 or later
  • Vormetric Data Security Manager (DSM) V6.2
  • Thales CipherTrust Manager 2.5.x or 2.8 or later
  • HashiCorp Vault Enterprise 1.12 or later
  • IBM Key Protect with Key Management Interoperability Protocol (KMIP)
    Note: Key server hosts are not required to be members of the IBM Storage Scale clusters that use them.
  Key server nodes are not required to be members of the IBM Storage Scale cluster(s) that use them.
  For ISKLM:

  • IBM Security Guardium Key Lifecycle Manager (GKLM) V5.0.0 is supported with the IBM Storage Scale Encryption feature.
  • IBM Security Guardium Key Lifecycle Manager (GKLM) V4.2.1 is supported with the IBM Storage Scale Encryption feature.
  • IBM Security Guardium Key Lifecycle Manager (GKLM) V4.1.1 is supported with the IBM Storage Scale Encryption feature.
  • IBM Security Guardium Key Lifecycle Manager (GKLM) V4.1.0.1 (IF01) is supported with the IBM Storage Scale Encryption feature.
  • ISKLM is not shipped with nor licensed with IBM Storage Scale and must be purchased separately.
  • ISKLM V2.6, or later of the server software (D0887LL) must be installed on each node that acts as a key server.
  • See the IBM Security Key Lifecycle Manager documentation for details about licensing that offering.
  For Vormetric:

  • Vormetric Data Security Manager is not shipped with nor licensed with IBM Storage Scale and must be purchased separately. Contact Vormetric directly to purchase.
  • Vormetric Data Security Manager is not supported on nodes installed with Linux on Z.
  For Thales CipherTrust Manager:

  • Thales CipherTrust Manager is not shipped with nor licensed with IBM Storage Scale and must be purchased separately. Contact Thales directly to purchase.
  For HashiCorp Vault:

  • HashiCorp Vault is not shipped with nor licensed with IBM Storage Scale and must be purchased separately. Contact HashiCorp directly to purchase.
• Every node that accesses the encrypted data must be running the Advanced Edition or Data Management Edition of IBM Storage Scale.
• Every node that accesses the encrypted data, and also nodes which play a management role in the file system (such as manager node, an NSD server, or a node which participates in the restripe of a file system), must have network connectivity to the key server.
• IBM Storage Scale client nodes do not require a key server license.
• Vormetric DSM V6.0.2, V6.0.3, and V6.1.x releases are not supported with IBM Storage Scale encryption. The user interface in these releases does not support the creation of KMIP objects such as the Master Encryption Keys (MEKs) that are used by IBM Storage Scale encryption. For more information, see https://www-01.ibm.com/support/docview.wss?uid=ibm10734479.
• Vormetric DSM V6.2 user interface supports the creation of KMIP objects such as the Master Encryption Keys (MEKs) used by IBM Storage Scale encryption. IBM Storage Scale encryption is supported with Vormetric DSM V6.2.
• For IBM Key Protect with KMIP:
  • IBM Key Protect with KMIP is available in IBM Cloud. For more information, see IBM Key Protect for IBM Cloud.
  • To use IBM key Protect with KMIP in IBM Storage Scale, the regular setup is required. For more information, see Regular setup: Accessing a remote file system.

Current limitations of the IBM Storage Scale encryption function include:

• Only user data is encrypted. The encryption of directories or other metadata is not supported.
• Extended attributes are not encrypted.
• Data, which is backed up, is in cleartext unless encryption is supported by the backup system.
• Data, which is migrated to tape using software such as IBM Storage Protect or IBM Spectrum Archive, is in cleartext unless the tape system and the connection between them (if Ethernet or InfiniBand) provide encryption.
• Encryption is not supported on Windows. The encryption function should be disabled when Windows nodes are in the cluster.
• The contents of encrypted files are placed into a local read-only cache (LROC) based on the settings of the lrocEnableStoringClearText configuration option. For more information, see the "Encryption and local read-only cache (LROC)" section.
• For more information, see Encryption requirements and limitations and Q6.12 How should IBM Storage Scale Advanced Edition or Data Management Edition be configured to only use FIPS 140-2-certified cryptographic engines?

Q2.13:

Are there any considerations when utilizing the Simple Network Management Protocol (SNMP)-based monitoring capability in IBM Storage Scale?

A2.13:

Considerations for the use of the SNMP-based monitoring capability include:

• The SNMP collector node must be a Linux node in your GPFS cluster. GPFS utilizes Net-SNMP which GPFS does not support on AIX.
• Support for ppc64 requires the use of Net-SNMP 5.4.1. Binaries for Net-SNMP 5.4.1 on ppc64 are not available. You will need to download the source and build the binary. Go to http://net-snmp.sourceforge.net/download.html
• If the monitored cluster is relatively large, you need to increase the communication time-out between the SNMP master agent and the GPFS SNMP subagent. In this context, a cluster is considered to be large if the number of nodes is greater than 25, or the number of file systems is greater than 15, or the total number of disks in all file systems is greater than 50. For more information see Configuring Net-SNMP in the IBM Storage Scale: Problem Determination Guide.
• SNMP-based monitoring has not been tested in clusters composed of more than 127 nodes.

Q2.14:

What are the current limitations and advisories for using the mmbackup command?

A2.14:

Current limitations and advisories include:

• Beginning with IBM Storage Scale V4.2, in file systems that are managed by an HSM system, mmbackup will skip over candidates for backup that are migrated offline to avoid causing a recall storm. Instead, records for these files will be added to a file in the root of the fileset called mmbackup.hsmMigFiles.name of server. System managers should recall these changed files online to allow mmbackup to properly protect them in the next invocation.
• File systems with IBM Storage Protect for Space Management that have unlinked filesets, will be required to link all filesets when issuing the mmbackup command for the first time after you upgrade GPFS cluster from GPFS 3.5.0.10 or lower, to GPFS 3.5.0.11 or higher. If you have any concerns regarding this requirement, please contact GPFS service.
  • In the United States contact us toll free at 1-800-IBM-SERV (1-800-426-7378)
  • In other countries, contact your local IBM Service Center
• Use of the IBM Storage Protect Backup-Archive client option SKIPACLUPDATECHECK with the mmbackup command requires IBM Tivoli Storage Manager release 6.4.1.0 or later.
  Note: Beginning with Version 7.1.3, IBM Tivoli Storage Manager is now IBM Storage Protect.
• The GPFS mmbackup command is not integrated with the IBM Storage Protect for Space Management-Multi HSM Server feature. See Managing a file system with multiple Tivoli Storage Manager servers.
• Restoring a file via a node that has a different architecture than the one used to do the backup could cause the associated ACL to be corrupted.

  For example, if a file was backed up using an x86_64 node, and then restored using a ppc64 node, this could cause its ACL to be corrupted (caused by differences in endianness of the architectures which is not supported by the GPFS APIs used in the restore operation). It is recommended that backup and restore operations be done on similar types of nodes.

• The mmbackup command supports backup of a whole file system from a global snapshot.

  The mmbackup -S snapshot command option is supported with IBM Storage Scale V4.1.1 on either a global snapshot for the whole file system or for a fileset backup if the fileset was captured in that snapshot. It is also supported with a fileset snapshot for a fileset backup, providing the name of the snapshot is unique among all snapshot names. Do not use the same snapshot name for multiple snapshots.

  The mmbackup -S snapshot command option is supported with GPFS V3.5.0.3 or later. GPFS V3.4 and GPFS V3.5.0.2 or lower do not support backup from a snapshot. If the snapshot directory for global snapshots and the directory for fileset level snapshots are different, then GPFS V3.5.0.4 or higher level is required.

  • Doing backup from a snapshot in an IBM Storage Protect for Space Management managed file system could cause recall of migrated files.

    In an HSM managed file system such as IBM Storage Protect for Space Management, using mmbackup to back up from a snapshot could cause the recall of migrated files if the migration was done after the snapshot was taken. This is due to the fact that a snapshot is a static view of the file system which does not reflect migration state changes. To avoid recalling data from migrated files, create the snapshot and complete the backup operation before migrating files or make sure that migration is done before the snapshot is taken for a backup operation. Backup operations will not recall files if the snapshot captured the files in their migrated state. Until and unless the migrated file stubs are removed from the live file system. In this case a recall will be required to populate the contents of the snapshot view of the files. If a snapshot exists, consider recalling files by using the IBM Storage Protect for Space Management "tape optimized recall" function before deleting migrated files from the active file system.

  • Doing backup from a snapshot in an IBM Storage Protect for Space Management managed file system could cause failure to backup migrated files.
• The use of unsupported characters in the names of files or directories will cause failures.

  mmbackup uses the IBM Storage Protect Backup Archive client to backup data to the IBM Storage Protect server. As IBM Storage Protect currently does not support all special characters in file or directory names, they cannot be supported by mmbackup. If special characters are used in the names of files or directories backed up by the mmbackup command, failures will result. Known special characters which can cause problems include: *, ?, ", ', control-X, control-Y, carriage return and the new line character. Use of the IBM Storage Protect options QUOTESARELITERAL and WILDCARDSARELITERAL along with the --noquote command line option to mmbackup will allow support for all special characters except carriage return, new line, control-X, and control-Y.

• Beginning with IBM Storage Scale V4.1.1, backup of either the entire file system or a selected fileset is supported. Nested fileset arrangements where one fileset is linked inside another are not supported by mmbackup on a fileset. Nesting remains supported for whole file system mmbackup. The first mmbackup of any fileset must be made using the option -t full to avoid causing accidental invalidation of existing backups that may exist of previously existing nested filesets.
• Differences in the way the mmbackup command and IBM Storage Protect process the include and exclude statements in the dsm.sys configuration file may cause files or directories to be included or excluded unexpectedly.
  Known differences in processing include, but are not limited to:

  • The mmbackup command does not support exclude.archive, exclude.file.spacemgmt, exclude.spacemgmt, exclude.fs.
  • Whether or not there is a / at the end of an exclude.dir affects the way mmbackup decides what files or directories are excluded.
  • exclude.file may cause incorrect files to be backed up if the pattern presents a wildcard at the end.

Q2.15:

What are the current limitations and advisories for using Scale Out Backup and Restore (SOBAR) ?

A2.15:

Current limitations and advisories include:

• IBM Storage Scale Image Backup and Restore (SOBAR) has been tested in a standalone manner; but must be tested with Data Management/HSM products before deployment by customers with such products in production environments. Customers who are interested in making use of this function should contact scale@us.ibm.com.
• SOBAR does not support the backup or restore of a file system with Active File Management (AFM) filesets.
• SOBAR supports backup from a global snapshot. Independent fileset snapshots are not supported.

Q2.16:

What are the current limitations for using the File Placement Optimizer (FPO) function?

A2.16:

Current limitations include:

• The File Placement Optimizer (FPO) function is supported on IBM Storage Scale GPFS V5, V4, and V3.5 for both the Linux and AIX operating systems. For V3.5, the Linux (x86 and Power) operating system requires APAR IV28687 and the AIX operating system requires APAR IV40108.
• AFM ADR (primary/secondary filesets) is not supported on an FPO enabled file system.
• With the AFM function, if you want to maintain data locality on both home and cache, they must have the same Failure Group configuration. Additionally, block placement policy must be set via write-affinity-failure-group at both sites.
• Twin-tailed disks are supported in an FPO pool only when a single NSD server is defined for each disk.
• Nodes running the GPFS File Placement Optimizer feature cannot coexist or interoperate with nodes running GPFS V3.4 or earlier releases of GPFS.
• Contact scale@us.ibm.com if you plan to deploy a cluster with more than 32 nodes in a Shared Nothing Cluster, or SNC, in which no disks in the cluster are served by more than a single node. This includes FPO nodes. Shared Nothing Clusters that are larger than 32 nodes must be reviewed and approved by IBM before deployment. This limitation applies to clusters that have more than 32 nodes that have disks serving a file system with data replication enabled, and these disks are only accessible from a single node.
  Note: You can determine if a given file system has data replication enabled by checking if the -R setting (the maximum number of data replicas) reported by the /usr/lpp/mmfs/bin/mmlsfs command is greater than 1.
• If a storage pool is FPO-enabled (allowWriteAffinity=yes), then layoutMap=cluster must also be specified.
• With GPFS V3.5, use of the mmrestripefile, mmadddisk -r and the mmrestripefs commands will break the original FPO file's placement.
• With GPFS V4.1, use of the mmrestripefile -b, mmadddisk -r and the mmrestripefs -b commands will break the original FPO file's placement.
• With GPFS V4.1, use of the mmrestripefile -r and the mmrestripefs -r commands is supported with locality awareness. Use of the commands with clones and snapshots will break the original FPO file's placement.
• On clusters with the FPO function enabled, in order to utilize the mmrestorefs command, you must specify the write-affinity-failure-group policy.
• If the size of a file is less than the value of the block size divided by 32, the write affinity depth policy and the write affinity failure group policy will not be followed. Data is widely striped instead.
• The setXattr function cannot set the FPO extended attributes writeAffinityDepth, write-affinity-failure-group, and BlockGroupFactor for a clone file or the policy MIGRATE rule. Respectively, setWAD, setWADFG, and setBGF should be used.
• The extended attributes writeAffinityDepth, write-affinity-failure-group, and BlockGroupFactor are for use only on an FPO pool.
• Starting in IBM Storage Scale 5.0.5, FPO and SNC remain available. However, it is recommended to limit the size of deployments to 32 nodes. There are no plans for significant new functionality in FPO nor increases in scalability. The strategic direction for storage using internal drives and storage rich servers is IBM Storage Scale Erasure Code Edition.
• The FPO configuration is not supported on IBM Storage Scale Erasure Code Edition.
  • Preparing for the IBM Storage Scale Erasure Code Edition environment: https://www.ibm.com/support/knowledgecenter/STXKQY_BDA_SHR/bl1bda_prepece.htm
  • Restrictions: https://www.ibm.com/support/knowledgecenter/STXKQY_5.0.5/com.ibm.spectrum.scale.v5r05.doc/bl1adv_fporestrictions.htm

Q2.17:

What are the current limitations for using the Active File Management (AFM) Async DR function?

A2.17:

Limitations are added and deleted from time to time. For more information about the limitations that affect a particular release, see the AFM limitations section under Product Overview > Active File Management in the Knowledge Center or in the IBM Storage Scale: Concepts, Planning, and Installation Guide.

Q2.18:

What are the current limitations for using the Active File Management (AFM) function?

A2.18:

Limitations are added and deleted from time to time. For more information about the limitations that affect a particular release, see the AFM limitations section under Product Overview > Active File Management in the Knowledge Center or in the IBM Storage Scale: Concepts, Planning, and Installation Guide.

Q2.19:

What are the current limitations common to both the Active File Management (AFM) and AFM DR functions?

A2.19:

Limitations are added and deleted from time to time. For more information about the limitations that affect a particular release, see the AFM and AFM DR limitations section under Product Overview > Active File Management in the Knowledge Center or in the IBM Storage Scale: Concepts, Planning, and Installation Guide.

Q2.20:

What is the currently recommended transport protocol for AFM and AFM DR data transfers?

A2.20:

For the current recommendations regarding the transport protocol for AFM and AFM DR data transfers, see The backend protocol - NFS versus NSD in the IBM Storage Scale: Concepts, Planning, and Installation Guide.

Q2.21:

What is the current limitation for using the snapshot restore function?

A2.21:

For mixed clusters containing GPFS V3.5, IBM Storage Scale 4.1.0, 4.1.0.4, 4.1.1, or V4.2 nodes, it is recommended that for both fileset and global snapshot restore, the mmrestorefs command is issued from a node running the most recent version of IBM Storage Scale. Version 4.1.1 and later, provides some new snapshot restore functionality so IBM Storage Scale attempts to intelligently use the latest features.

Note:

1. IBM Storage Scale V4.2 only interoperates with IBM Storage Scale V4.1
2. The mmrestorefs command is not supported on the Express Edition.

• To improve performance support for the –N parameter on the mmrestorefs command has been phased in over the past few releases.
  • In GPFS 3.5 and earlier there is no –N parameter
  • In GPFS 4.1 –N can be used for fileset snapshot restore only
  • In IBM Storage Scale 4.1.1 and later –N can be used for both fileset and global snapshot restores
• For global snapshot restore:
  • If the mmrestorefs command is issued from a pre-4.1.1 node:
    1. The file system must be unmounted.
    2. The file system manager performs the restore.
  • If the mmrestorefs command is issued from a 4.1.1 or later node:
    • The file system must be mounted.
    • By default the restore is performed on all nodes running the latest level of code.
• For fileset snapshot restore:
  • If the mmrestorefs command is issued from a V3.5 node:
    1. The file system must be unmounted.
    2. The file system manager performs the restore.
  • If the mmrestorefs command is issued from a 4.1 or later node:
    • The file system must be mounted.
    • By default the restore is performed on all nodes running the latest level of code.

Q2.22:

What are the current requirements when using local read-only cache?

A2.22:

The current requirements/limitations for using local read-only cache include:

• A minimum of IBM Storage Scale V4.1.0.1.
• Local read-only cache is only supported on Linux x86 and Power.
• The minimum size of a local read-only cache device is 4 GB.
• The local read-only cache requires memory equal to 1% of the local read-only device's capacity.

Note: Use of local read-only cache does not require a server license

Q2.23:

What are the current requirements/limitations for using the Cluster Configuration Repository (CCR) ?

A2.23:

The current requirements/limitations for using the Cluster Configuration Repository (CCR) include:

• IBM Storage Scale V4.1.0: The Disaster Recovery procedures described in the Advanced Administration Guide are not supported in a cluster with CCR enabled:
  • Do not run mmchcluster --ccr-enable for existing clusters
  • Use mmcrcluster --ccr-disable for new clusters
• IBM Storage ScaleV4.1.1, or later, there are no limitations for using CCR.

Q2.24:

What are the current requirements/limitations for using Ubuntu?

A2.24:

The current requirements/limitations for using Ubuntu include:

• The minimum level of Ubuntu supported is 14.04.1.
• Only IBM Storage Scale 4.1.0.8 or later, is supported with 14.04.2.
• Only IBM Storage Scale 4.1.1.9/4.2.1.1 or later is supported with 14.04.4/16.04.
• The minimum kernel level supported is 3.13.0.32.
• Only IBM Storage Scale 4.2.3.10/5.0.1.2 or later is supported with 18.04.1.
• Only IBM Storage Scale for Linux on Z 4.2.3.10/5.0.1.2 or later is supported with 18.04.
• P8 is supported with Little Endian only and only with GPFS for Linux on System p base RPMs dated January 2015 (GPFS V4.1.0.5 or later).
  If you have Software Maintenance Agreement (SWMA) for your products ordered through AAS/eConfig or IBM Subscription and Support (S&S) for orders placed through Passport Advantage, you may log into the respective systems and upgrade your level of GPFS:

  • For products ordered through AAS/eConfig, please log into the Entitled Software page at: https://www-05.ibm.com/servers/eserver/ess/OpenServlet.wss
  • For products ordered through Passport Advantage, please log into the site at: http://www.ibm.com/software/lotus/passportadvantage/
• GPFS V3.5.0.22 or later is only supported on x86_64 architecture
• When issuing make World for Ubuntu 14.04.1, this warning will appear but can be disregarded because kdump-kern-dummy.ko is not utilized by GPFS.
  WARNING: ".TOC." [/usr/lpp/mmfs/src/gpl-linux/kdump-kern-dummy.ko] undefined!
• As Tivoli Storage Manager (TSM) does not support Ubuntu, GPFS commands that utilize TSM are not supported on Ubuntu.
  Note: Beginning with Version 7.1.3, IBM Tivoli Storage Manager is now IBM Storage Protect.
• If you use CNFS or CES features under Ubuntu, verify that the iputils-arping package is installed. See the Software requirements page for more information.

Q2.25:

What are the current requirements/limitations for IBM Storage Scale for Linux on Z?

A2.25:

The current requirements and limitations for IBM Storage Scale for Linux on Z include:

• A leapp upgrade from Red Hat Enterprise 7.x to 8.x is not supported.
• File Placement Optimizer is not supported.
• For support of backup and restore functions with IBM Storage Scale for Linux on Z, see the following support matrices:
  Note: Starting with IBM Storage Scale V5.0.0, the IBM Storage Protect for Space Management client is no longer supported on IBM Storage Scale for Linux on Z.
  • For the IBM Storage Protect Backup Archive client, see Hardware and software requirements for IBM Storage Protect Linux zSeries Backup-Archive and API Client.
  • For the IBM Storage Protect for Space Management client, see IBM Storage Protect for Space Management (HSM) requirements for Linux on IBM z Systems®.
• For supported storage, see the What disk hardware has IBM Storage Scale been tested with? and the IBM Storage Scale for Linux on Z support Direct Attached Storage Devices (DASD)? questions.
• Support for stretched cluster with synchronous mirroring utilizing block-level replication:
  • For IBM Storage Scale 5.0.0 and later, with distances up to 300 km.
• Kernel NFS (v3 and v4) is supported. Clustered NFS function (CNFS) is not supported.

Note:

1. Central Processor Assist for Cryptographic Function (CPACF) is supported. CPACF is IBM Z hardware encryption acceleration. It is incorporated in the central processors that are shipped with IBM Z. To benefit from the CPACF, you must install LIC internal feature 3863 (Crypto Enablement feature), which is available free of charge. By default, IBM Z is delivered to customers without this feature unless it is ordered explicitly by the customer. The installation of this feature at a future time is nondisruptive.
2. IBM z15 and z16 offer the Integrated Accelerator for zEnterprise®® Data Compression (zEDC). This feature is enabled by default starting from IBM Storage Scale 5.1.0 when the CPU feature 'dflt' is listed in /proc/cpuinfo. Compression options such as z, zfast, alphae and alphah benefit from this feature. The feature also depends on your installed zlib version. For more information, see https://linux.mainframe.blog/zlib-acceleration/ for details.

Q2.26:

What is the Highly-Available Write Cache (HAWC) function?

A2.26:

The Highly-Available Write Cache (HAWC) function available with IBM Storage Scale V4.1.1.1 or later, reduces the latency of bursts of small write requests by buffering them in fast storage such as SSDs.

Note: If you plan on using the HAWC function on client nodes, V4.1.1.2 is required.

The HAWC function can benefit numerous applications such as VMs, appending to logs and many more. If a file system's metadata is already stored on fast storage such as SSDs, then the feature can be simply enabled with very little effort. If not, then a new 'fast storage' pool must be created on either one or more NSD servers or on the clients themselves. HAWC is controlled via the file system parameter write-cache-threshold and can also be used with existing as well as new file systems. For more information, see the IBM Storage Scale: Advanced Administration Guide at http://www-01.ibm.com/support/knowledgecenter/STXKQY/411/com.ibm.spectrum.scale.v4r11.adv.doc/bl1adv_hawc.htm?lang=en

Q2.27:

What are the current requirements/limitations for the deadlock amelioration function in IBM Storage Scale?

A2.27:

The current requirements/limitations for use of the deadlock amelioration function include:

• Deadlock amelioration functions are fully supported in IBM Storage Scale V4.
• In a cluster with minReleaseLevel below 4.1.0, that consists of all GPFS 4.1 nodes or a mixture of 4.1 and 3.5 nodes, the deadlock amelioration functions may still work partially. In order to avoid a problem of tracing not being turned off after GPFS code turns it on make sure to have 3.5.0.24 or later, or 4.1.0.7 or later, or have APAR IV69797 applied to all nodes. Running with tracing on could have performance implications.

Q2.28:

What are the requirements/limitations for using the IBM Storage Scale GUI?

A2.28:

Considerations for using the IBM Storage Scale GUI include:

• The GUI is available with the Standard and Advanced Editions for Linux on x86, Linux on Z, and Power (Big Endian and Little Endian).
• The GUI is supported on RHEL 7.1 or later, SLES 12 SP1 and SP2, and Ubuntu 16.4 on Linux x86, Linux on POWER, and Linux on z platforms. For more information, see 2.1 What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?.
• The maximum number of nodes supported is:
  • With V4.2.1 and later, 1000 nodes
  • With V4.2, 128 nodes
• When planning to add GUI nodes with the Installation Toolkit, add them via spectrumscale install or spectrumscale deploy, either before performing an upgrade to 4.2.0.1 or later. Attempting to add GUI nodes during the upgrade itself may result in a failure during the Upgrading Performance Monitoring step.
• The GUI works with either a client or server license.
• The GUI depends on a pre-installed PostgreSQL server usually installed already with the operating system installation but if this is not the case if you install the operating system from scratch you need to do this before you install the GUI or the installation fails.

Q2.29:

What are the requirements/limitations for using the compression function?

A2.29:

Compression support excludes the following:

• Compressing files in snapshots.
• Compressing clones and cloning compressed files.
• Small file compression (files consuming less than 2 sub-blocks, compressing small files into inode).
• Compression of non-regular files, such as directories.
• Compression of files in Windows hyper allocation mode.
• File compression does not compress a memory-mapped file.
• File compression does not compress a file that is opened for Direct I/O.

Additionally:

• Compression is supported in an FPO environment or horizontal storage pools with IBM Storage Scale V4.2.1 and later.
• Compression in this release is optimized for cold data or write-once objects and files. It uses the zlib data compression library and favors saving space over speed. Usage on other types of data may result in performance degradation.
• On Windows:
  • Compression of a file on Windows is only enabled via the mmchattr command.
  • The following Windows APIs are not supported:
    • FSCTL_SET_COMPRESSION to enable/disable compression on a file
    • FSCTL_GET_COMPRESSION to retrieve compression status of a file
  • In Windows Explorer, in the Advanced Attributes window, the compression feature is not supported.
• On IBM Z:
  • The IBM zEDC hardware compression feature is enabled by default starting from IBM Storage Scale 5.1.0 when the CPU feature 'dflt' is listed in /proc/cpuinfo. Compression options such as z, zfast, alphae and alphah benefit from this feature. The feature also depends on your installed zlib version. For more information, see https://linux.mainframe.blog/zlib-acceleration/.

Q2.30:

What are the requirements/limitations for using the Quality of Service (QoS) function?

A2.30:

Considerations for using the Quality of Service function include:

• Only four file system wide system classes are supported: maintenance, other, misc and mdio-sharing-class, while user class can be created based on user's request and can be used only after associating with a specific fileset.
• User applications can be throttled differently by operating on different fileset.
• The mmqos command is available only for the Linux operating system.
• The QoS system classes cannot associate with filesets.
• By default, the QoS system classes do not support MDIO.
• For Linux on Z, Quality of Service is only supported with V4.2.1 and later.
• No throttling for applications which perform direct I/O.
• Not supported on AFM cache and AFM-based asynchronous DR filesets.
• For IBM Storage Scale V4.2.1 and later, QoS is supported in an FPO environment.
• The following flash for QoS was issued:

  Abstract:

  In an IBM Storage Scale V4.2 file system with multiple storage pools, Quality of Service (QoS) settings should be set for all storage pools to avoid performance degradation for unspecified storage pools.

  Problem Summary:

  In an IBM Storage Scale V4.2 file system with multiple storage pools, if the user specifies Quality of Service for I/O operations (QoS) settings (for the maintenance and other classes) only for one storage pool then the I/O allocations for the unspecified pools will be set to a very low value, resulting in severe performance degradation when I/O is performed to the unspecified storage pool(s).

  See the complete Flash at http://www.ibm.com/support/docview.wss?uid=ssg1S1005464

Q2.31:

What are the considerations when running on SELinux?

A2.31:

The following considerations apply to running SELinux:

• From the 5.0.5 release, IBM Storage Scale runs on Red Hat Enterprise Linux operating systems with Security-Enhanced Linux (SELinux). For more information, see the Security-Enhanced Linux support topic in the IBM Storage Scale: Concepts, Planning, and Installation Guide.
• When using the installation toolkit, the IBM Storage Scale Swift Object protocol functionality requires the following SELinux packages to be installed:
  • selinux-policy-base at 3.13.1-23 or higher
  • selinux-policy-targeted at 3.12.1-153 or higher
• When using the Swift Object protocol functionality, enabling SELinux after IBM Storage Scale has been installed is not supported. Contact IBM Storage Scale support at scale@us.ibm.com if you have questions about this restriction.

Q2.32:

What enhancements to quota management are available?

A2.32:

Enhancements to quota management available with IBM Storage Scale V4.1 and later, allow for quota clients to dynamically acquire and relinquish quotas based upon consuming rate; that is, the quota manager grants quota shares based upon global quota information such as the remaining quota limit and the number of mounted clients. Decisions based upon existing information provides for greater efficiency in managing quotas, however, this could result in an increase in the in-doubt values from earlier releases when running with a heavy IO workload. In order to get more accurate usage, issuing the mmlsquota and mmrepquota commands with the -e option might help.

Note: Quota report accuracy is mainly affected by hardware errors, such as node/network failures. Having a large number of nodes could increase the chances of having these types of failures.

Q2.33:

What are the current limitations of quota management?

A2.33:

The aggregate total number of quota records in user, group, and fileset quota files is limited to 200K records per file system. This limitation is due to the maximum amount of data that can be exchanged between the quota manager and quota command client such as the mmrepquota command.

Note: A large number of quota records per file system can result from the following scenarios:

• There are a very large number of users, groups, or filesets.
• If the --perfileset-quota option is enabled, the number of possible quota records is the number of filesets times number of users (and groups).

Q2.34:

Is file immutability supported with IBM Storage Scale?

A2.34:

Yes. For more information about IBM Storage Scale immutability functions, configuration, and operation, see Immutability and appendOnly features in the IBM Storage Scale: Administration Guide and the following Redpaper: http://www.redbooks.ibm.com/abstracts/redp5507.html.

Q2.35:

Has file immutability been assessed for compliance?

A2.35:

The immutability function of IBM Storage Scale 5.1.0 has been assessed for compliance in accordance to Securities and Exchange Commission (SEC) Rule 17a-4(f), Financial Industry Regulatory Authority (FINRA) Rule 4511(c) and the principles-based electronic records requirements of the Commodity Futures Trading Commission (CFTC) in 17 CFR § 1.31(c)-(d). To view the detailed assessment report, see IBM Storage Scale Assessment Report.

The immutability function of IBM Storage Scale 5.0.0 has been assessed for compliance in accordance to US SEC17a-4f, EU GDPR Article 21 Section 1, German and Swiss laws and regulations by a recognized auditor. For more information, see the following links:

Assessment report: http://www.kpmg.de/bescheinigungen/RequestReport.aspx?B290411BE1224F5A9B4D24663BCD3C5D

Certificate: http://www.kpmg.de/bescheinigungen/RequestReport.aspx?DE968667B47544FF83F6CCDCF37E5FB5

Q2.36:

Is there any guidance for RHEL 8 installations on IBM Storage Scale?

A2.36:

Python 2 needs to be installed on new RHEL 8 installations because it is not installed by default. It is recommended that you create both the RHEL 8 BaseOS and AppStream repositories so that the package dependencies are met during installation.

If you intend to perform a leapp upgrade from RHEL 7.6 (versus a first-time installation) to RHEL 8, keep the following information in mind:

1. It is highly recommended that you use leapp-0.8.1-1 or higher. Make sure that the following requirements are met and the latest RHEL upgrade procedure is followed: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html-single/upgrading_to_rhel_8/index
2. Consider running the boom utility to manage more boot loader entries on the system and to provide a path back to RHEL 7.6 if necessary: https://www.redhat.com/en/blog/upgrading-rhel-7-rhel-8-leapp-and-boom
3. As of the 5.0.4 release, if IBM Storage Scale 5.0.4 packages are installed and the leapp upgrade utility is run, leapp might remove some IBM Storage Scale packages and some dependencies. Manually reinstalling the removed packages will be required. Either proceed at your own risk, or consider not using the leapp upgrade utility and provisioning a new RHEL 8 node.
4. If protocols and authentication are enabled, python-ldap needs to be installed for mmadquery to run. A leapp upgrade from RHEL 7.x to RHEL 8.x removes the python-ldap package, which is a prerequisite for mmadquery. Ensure that you install python-ldap after the leapp upgrade if you intend to use mmadquery on RHEL 8.x.

Note:

• RHEL 8 is not supported by the Swift Object protocol in releases earlier than IBM Storage Scale 5.1.0.
• RHEL 8 is supported by Transparent cloud tiering starting with IBM Storage Scale 5.0.5.

For more information, see Guidance for Red Hat Enterprise Linux 8.x on IBM Storage Scale nodes in the IBM Storage Scale: Concepts, Planning, and Installation Guide.

Q2.37:

What are the requirements/limitations for using the file clone function?

A2.37:

The following requirements and limitations apply to using the file clone function:

• A compressed file cannot be cloned and a clone file cannot be compressed.
• mmap is not supported on clone child files.

Q2.38:

What are the requirements/limitations for using the memory-mapped (mmap) function?

A2.38:

mmap is not supported on clone child files.

Q2.39:

Are IBM Storage Scale packages signed by IBM?

A2.39:

Starting with the IBM Storage Scale release 5.0.4, all IBM Storage Scale packages on Red Hat Enterprise Linux and SLES operating systems on supported architectures are signed by IBM with a GPG key. Starting with the IBM Storage Scale release 5.0.5.1, repository metadata is also signed by IBM.

You can use the available public key to verify the signatures on the packages and repository metadata.

The latest public key contents are as follows:

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: EKM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=v7fu
-----END PGP PUBLIC KEY BLOCK-----

Save these contents in a file and import it to verify the signature manually. The installation toolkit does the signature verification automatically before installation or upgrade. For more information, see https://www.ibm.com/support/knowledgecenter/STXKQY_5.0.5/com.ibm.spectrum.scale.v5r05.doc/bl1ins_verifysignature.htm.

Q2.40:

What are the components required for GPUDirect Storage (GDS) support with IBM Storage Scale?

A2.40:

The following software components are required for GPUDirect Storage (GDS) support with IBM Storage Scale:

• The required IBM Storage Scale version depends on the fabric type over which GPUDirect Storage is run:
  • Infiniband: IBM Storage Scale 5.1.2 or later.
  • RoCE: IBM Storage Scale 5.1.3 or later.
  • The recommended version is IBM Storage Scale 5.1.6 as it includes accelerated GDS writes.
• Linux distros:
  • For GDS clients: Ubuntu 20.04, RHEL 8.4, RHEL 8.6.
  • For storage servers: Any Linux distro that supports IBM Storage Scale 5.1.2 (Infiniband), 5.1.3 (Infiniband, RoCE) or later.
• Mellanox OFED: MOFED v5.4-1.0.3.0, MOFED v5.6-2.0.9.0
• Nvidia CUDA
  • Infiniband: CUDA 11.4.2, CUDA 11.5.1, CUDA 11.6.2, CUDA 11.7, CUDA 11.8
  • RoCE: CUDA 11.5.1, CUDA 11.6.2, CUDA 11.7, CUDA 11.8
  • CUDA 11.8 is required for accelerated GDS writes

Note:

• IBM Storage Scale 5.1.6 introduces accelerated GDS writes. For more information, see GPUDirect Storage support for IBM Storage Scale.
• Asynchronous CUDA IO is not supported.
• The IBM Storage Scale 5.1.1 technical preview is not compatible with IBM Storage Scale 5.1.2 and later.

References:

• For more information and supported hardware, see Planning for GPUDirectStorage in the IBM Storage Scale: Concepts, Planning, and Installation Guide.
• For the base configuration of IBM Storage Scale on RoCE fabrics, see Highly Efficient Data Access with RoCE on IBM Elastic Storage Systems and IBM Storage Scale.

Q2.41:

What are the requirements/limitations for manipulating the system.nfs4_acl extended attribute directly in IBM Storage Scale?

A2.41:

The following are the requirements/limitations for manipulating the system.nfs4_acl extended attribute directly in IBM Storage Scale:

• Manipulating the system.nfs4_acl extended attribute is supported only on Linux.
• It is recommended to use version 0.4.2 or later when installing the nfs4-acl-tools package.
• nfs4-acl-tools 0.4.2 and later versions are expected to work without problems.
• nfs4-acl-tools 0.3.6, 0.3.7, and 0.4.1 have the problem of showing the error message Invalid filename for all the errors that are returned from stat(). For example, if a directory does not have execute permission for user A and user A invokes nfs4_getfacl on a file within the directory, Invalid filename is returned instead of Permission denied. Version 0.3.7 is included in Ubuntu 22.04.
• nfs4-acl-tools 0.3.5 has the problem of showing undocumented flags O, G, and E, which can be ignored. For example, if the parent directory has ACE A:d:gpfsuser:rtncy, a subdirectory created under it will inherit the ACE with the additional O flag A:do:gpfsuser:rtncy, the O flag is not part of the protocol and can be ignored. This version is included in RHEL 8 and RHEL 9.
• nfs4-acl-tools 0.3.3 can run into segmentation faults. This version is not supported. This is included in RHEL 7, Ubuntu 20.04, SLES15 SP3, and SLES15 SP4.
• Listing the extended attributes through listxattr does not include the system.nfs4_acl attribute. This is to avoid redundant work in case of preserving xattrs with cp (cp --preserve=xattr), as the system.gpfs_nfs4_acl extended attribute already exists. The system.nfs4_acl attribute can still be retrieved with getxattr.
• In addition to strings, numeric IDs can also be accepted for the principal in a NFSv4 access control entry.
• To add new ACL entries to inodes that do not have NFSv4 ACL set and for inodes that have only mode bits, an equivalent NFSv4 ACL is created from the mode bits and returned when retrieving the attribute.
• When the file system allows only NFSv4 authorization (-k nfs4), and the inode has a POSIX ACL, a conversion from POSIX to NFSv4 for the ACL is performed when retrieving the attribute.
• When the file system allows both POSIX and NFSv4 authorizations (-k all) and the inode has a POSIX ACL, no conversion from POSIX to NFSv4 for the ACL is done when retrieving the attribute, and the query is denied. In this case, change the permission to mode bits or a NFSv4 ACL first before attempting to use the tools in the nfs4-acl-tools package.

Q2.42:

Does IBM Storage Scale support the secure boot specified by the Unified Extensible Firmware Interface (UEFI)?

A2.42:

IBM Storage Scale supports secure boot in the following ways:

1. For RHEL, the following scenarios are supported:
   1. IBM provides signed kernel modules together with a validation key starting with RHEL 9.2. on x86_64. For more information, see Signed kernel modules for UEFI secure boot.
   2. The kernel modules are signed manually by the customers with their key.
   3. Secure boot is disabled.
2. Secure boot is not supported with SLES or Ubuntu, which means that it has to be disabled in the BIOS.

Q2.43:

Is IBM Storage Scale supported on Advanced RISC Machine (ARM) architectures?

A2.43:

Yes. Starting with IBM Storage Scale 5.2.0, IBM Storage Scale is supported on ARM architectures. Before 5.2.0 was released, a technology preview was made available with IBM Storage Scale 5.1.9.0 through 5.1.9.4 (for more information, see ARM technology preview for IBM Storage Scale 5.1.9). IBM Storage Scale has been developed for ARM architectures with an instruction set of at least ARMv8.2-A.

IBM Storage Scale has been tested on systems based on Ampere Altra and Nvidia Grace Hopper processors. IBM Storage Scale has been successfully installed on AWS Graviton 2, AWS Graviton 3, and systems based on Fujitsu A64FX.

For information about the supported operating systems and kernels, see What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?.

The following features are not supported by release 5.2.0.x:

• NSD server (support starts with 5.2.1)
• IBM Storage Scale GUI (ARM nodes can be managed in the GUI but the GUI cannot run on an ARM node)
• Offline files (HSM)
• Kernel signing
• IBM Storage Scale GPFS native RAID (GNR); that is, Erasure Code Edition (ECE).
• Protocol servers: SMB, NFS, CNFS, Object, BDA

The packages for ARM can be recognized by the platform token “aarch64” or “arm64”. For example, gpfs.base-5.1.9-0.aarch64.rpm or gpfs.base_5.2.0-0_arm64.deb.

ARM technology preview for IBM Storage Scale 5.1.9

With IBM Storage Scale 5.1.9.0 through 5.1.9.4, IBM Storage Scale was supported on ARM architectures as a technology preview. Meaning, it was supported only for non-production environments. The ARM technology preview is superseded by the support made available with the 5.2.0 release; thus, no packages for ARM technology preview are available for 5.1.9.5 onward. Information about this technology preview is still available on the next IBM Support page: IBM Storage Scale Technical Preview: Support for ARM based processors.

Q2.44:

What are the requirements and limitations for using the asymmetric data replication function?

A2.44:

Currently, the use of asymmetric data replication for file systems is not supported.

The feature will be supported for specific configurations over time. The first use of asymmetric data replication for file systems will be supported as hyper store in an upcoming IBM Storage Scale System release. As new configurations become supported, this section of the FAQ will be updated to provide details.

Q3.1:

What are the minimum hardware requirements for an IBM Storage Scale cluster?

A3.1:

The minimum hardware requirements are:

• IBM zSystems:
  • 2 vcpu with 2 GB memory.
  • IBM Storage Scale V5.1.2 or later : Family z13 or later.
  • IBM Storage Scale V5.1.1 or earlier : Family z196 or later.
• IBM Storage Scale V5 on Power:
  • AIX on Power is supported by IBM POWER8 processors, or higher processors , supported by your level of AIX, with a minimum of 2 GB of system memory.
  • Linux on Power is supported on IBM POWER8, or higher processors, with a minimum of 2 GB of system memory.
  • POWER9 and Power10 CPUs support a new Radix MMU mode. The Linux kernel can use this MMU mode to implement additional restrictions for memory access, called Kernel Userspace Access Prevention (KUAP). IBM Storage Scale releases 5.1.3 and 5.1.2.5 have proper support for this feature. Earlier IBM Storage Scale releases require a workaround. The only affected Linux distribution by earlier IBM Storage Scale releases is Ubuntu 20.04. To verify whether the POWER9 and POWER10 feature is active, run the following command:

    grep Radix /proc/cpuinfo

    To check whether KUAP is active, run dmesg or check the syslog for the following message:

    radix-mmu: Activating Kernel Userspace Access Prevention

    If KUAP is active, modify the boot loader of your Linux distribution to pass the nosmap parameter to the Linux kernel. Then reboot and again run the above checks. Only when KUAP is no longer active, attempt to start IBM Storage Scale.

  Note: For more information about specific Power processor and operating system version requirements, see 2.1 What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?.
• IBM Storage Scale V4/IBM GPFS V3 or later on x86 architecture is supported on:
  • Intel 64 processors, with 2 GB of memory.
  • AMD Opteron processors, with 2 GB of memory. Other AMD x86-64 processors are supported as long as they are completely compatible with AMD Opteron, and as long as the SMP scaling limit is not exceeded. For more information, see 5.3 What is the current maximum tested limit for SMP scaling?.

Additionally, it is highly suggested that a sufficiently large amount of swap space is configured. While the actual configuration decisions should be made taking into account the memory requirements of other applications, it is suggested to configure at least as much swap space as there is physical memory on a given node.

IBM Storage Scale is supported on systems which are listed in, or compatible with, the IBM hardware specified in the Hardware requirements section of the Sales Manual for IBM Storage Scale.

To access the Sales Manual:

1. Go to the Recent sales manual section in the IBM Announcements site.
2. On Information Type, choose HW&SW Desc (sales manual,RPQ).
3. For IBM Storage Scale V5, choose the corresponding product number to enter in the Search for field:
   • IBM Storage Scale Data Access Edition: 5737-I39 (Passport Advantage), 5641-DA1, 5641-DA3, 5641-DA5 (eConfig/AAS)
   • IBM Storage Scale Data Management Edition: 5737-F34 (Passport Advantage), 5641-DM1, 5641-DM3, 5641-DM5 (eConfig/AAS)
   • IBM Storage Scale Erasure Code Edition: 5737J34 (Passport Advantage)
4. The Hardware Requirements section, which is part of the Technical Description section.

Q3.2:

On what servers is IBM Storage Scale supported?

A3.2:

1. IBM Storage Scale for Linux on Z is supported:
   1. with the distributions and kernel levels as listed in the question 2.1 What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?
   2. on servers that meet the minimum hardware model requirements as listed in the question What are the minimum hardware requirements for a IBM Storage Scale cluster?
2. IBM Storage Scale for AIX is supported:
   1. with levels of AIX as listed in the question 2.1 What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?
   2. on servers that meet the minimum hardware model requirements as listed in the question What are the minimum hardware requirements for a IBM Storage Scale cluster?
      Note: IBM Storage Scale runs on the POWER8 processor in default, POWER8, and POWER7 compatibility modes.
3. IBM Storage Scale for Linux on Power is supported:
   1. with the distributions and kernel levels as listed in the question 2.1 What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?
   2. on servers that meet the minimum hardware model requirements as listed in the question What are the minimum hardware requirements for a IBM Storage Scale cluster?
      Note: IBM Storage Scale runs on the POWER8 processor in default, POWER8, and POWER7 compatibility modes.
4. IBM Storage Scale for Linux on x86 Architecture is supported:
   1. with the distributions and kernel levels as listed in the question 2.1 What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?
   2. on servers that meet the minimum hardware model requirements as listed in the question What are the minimum hardware requirements for a IBM Storage Scale cluster?
   3. for additional support statements, see the question What are the current restrictions on IBM Storage Scale Linux kernel support?
5. IBM Storage Scale for Windows on x86 Architecture is supported:
   1. with the levels of Windows Server as listed in the question 2.1 What is supported on IBM Storage Scale for AIX, Linux, Power, and Windows?
   2. on servers that meet the minimum hardware model requirements as listed in the question What are the minimum hardware requirements for a IBM Storage Scale cluster?

Q3.3:

What interconnects are supported for GPFS daemon-to-daemon communication in a GPFS cluster?

A3.3:

The interconnect for GPFS daemon-to-daemon communication depends upon the types of nodes in your cluster.

Note: This table provides the list of communication interconnects which have been tested by IBM and are known to work with GPFS. Other interconnects may work with GPFS but they have not been tested by IBM. The IBM Storage Scale support team will help customers who are using interconnects that have not been tested to solve problems directly related to GPFS, but will not be responsible for solving problems deemed to be issues with the underlying communication interconnect's behavior including any performance issues exhibited on untested interconnects.

Table 34. GPFS daemon -to-daemon communication interconnects

Nodes in your cluster	Supported interconnect	Supported environments
Linux(x86 , Power)/AIX/Windows	Ethernet	All supported IBM Storage Scale environments
	10-Gigabit Ethernet 40-Gigabit Ethernet	All supported IBM Storage Scale environments
	InfiniBand	All supported IBM Storage Scale environments IP only
Linux (x86 and Power)	Ethernet	All supported IBM Storage Scale environments
	10-Gigabit Ethernet 40-Gigabit Ethernet	All supported IBM Storage Scale environments
	InfiniBand	IP and optionally VERBS RDMA Note: See the question Are there any considerations when utilizing the Remote Direct Memory Access (RDMA) offered by InfiniBand?
Linux on Z	Ethernet 10-Gigabit Ethernet 25-Gigabit Ethernet Hipersockets Vswitch (z/VM only) GuestLAN (z/VM only) ISM devices (SMC-D)	All supported IBM Storage Scale environments
AIX	Ethernet	All supported IBM Storage Scale environments
	10-Gigabit Ethernet 40-Gigabit Ethernet	All supported IBM Storage Scale environments
	InfiniBand	All supported IBM Storage Scale environments IP only
Windows	Ethernet	All supported IBM Storage Scale environments
	10-Gigabit Ethernet 40-Gigabit Ethernet	All supported IBM Storage Scale environments
	InfiniBand	All supported IBM Storage Scale environments IP only

Q4.1:

What disk hardware has IBM Storage Scale been tested with?

A4.1:

This set of tables displays the set of disk hardware which has been tested by IBM and known to work with IBM Storage Scale. Other disk devices may work with IBM Storage Scale using NSD disk leasing, though they have not been tested by IBM. The IBM Storage Scale support team will help customers who are using devices outside of this list of tested devices, using NSD disk leasing only, to solve problems directly related to IBM Storage Scale, but will not be responsible for solving problems deemed to be issues with the underlying device's behavior including any performance issues exhibited on untested hardware. Untested devices should not be used with GPFS assuming SCSI-3 PR as the fencing mechanism, since our experience has shown that devices cannot, in general, be assumed to support the SCSI-3 Persistent Reserve modes required by GPFS.

These test statements apply to all current releases of IBM Storage Scale unless specified otherwise.

It is important to note that:

• Each individual disk subsystem requires a specific set of device drivers for proper operation while attached to a host running GPFS. The prerequisite levels of device drivers are not documented in this GPFS-specific FAQ. Refer to the disk subsystem's web page to determine the currency of the device driver stack for the host's operating system level and attachment configuration.

  For information on IBM disk storage subsystems and their related device drivers levels and Operating System support guidelines, go to www.ibm.com/servers/storage/support/disk/index.html

• Microcode levels should be at the latest levels available for your specific disk hardware.

  For the IBM System Storage, go to www.ibm.com/servers/storage/support/allproducts/downloading.html

DS4000 customers: Please also see

• The IBM TotalStorage DS4000 Best Practices and Performance Tuning Guide at publib-b.boulder.ibm.com/abstracts/sg246363.html?Open
• For the latest firmware and device driver support for DS4100 and DS4100 Express Midrange Disk System, go to http://www.ibm.com/systems/support/supportsite.wss/selectproduct?brandind=5000028&familyind=5329597&osind=0&oldbrand=5000028&oldfamily=5345919&oldtype=0&taskind=2&matrix=Y&psid=dm
• For the latest storage subsystem controller firmware support for DS4200, DS4700, DS4800, go to:
  • https://www.ibm.com/systems/support/supportsite.wss/docdisplay?lndocid=MIGR-5075581&brandind=5000028
  • https://www.ibm.com/systems/support/supportsite.wss/docdisplay?lndocid=MIGR-5073716&brandind=5000028

Table 35. Disk hardware tested for AIX on Power

XtremIO 4.0.10 VMAX 3 Hudson 5977.810.784 and Trinity 5977.932.887 AIX 6.1 TL9 SP6, AIX 7.1 TL4 and AIX 7.2 or later, with IBM Storage Scale V4.1.0.0 or later

IBM FlashSystem® 900 Minimal Firmware Level: 1.2.0.11 This storage subsystem has been tested on AIX 7.1.3.16 with IBM Storage Scale V4.1.0.8 or later

IBM FlashSystem 840 Minimal Firmware Level: 1.1.1.2 AIX 6.1(6100-09) and AIX 7.1(7100-02-03-1334) with GPFS V3.5.0.19 or later, and IBM Storage Scale V4.1 or later

IBM FlashSystem 820 Minimal Firmware Level: 6.3.0.6 AIX 6.1(6100-06) and AIX 7.1(7100-01) with GPFS V3.5.0.11 or later, and IBM Storage Scale V4.1 or later

IBM Storwize® V7000/V3500/V3700/SVC Note: Placing GPFS metadata on thinly provisioned or compressed volumes is not supported. AIX 6.1 and 7.1 with GPFS V3.5 or later, and IBM Storage Scale V4.1 or later

IBM XIV® 2810 Minimum Firmware Levels: 10.1, 10.2 AIX 6.1 and 7.1 with GPFS V3.5 or later, and IBM Storage Scale V4.1 or later For more information, directions and recommended settings for attachment please refer to the latest Host Attach Guide for Linux located at the IBM XIV Storage System Knowledge Center go to http://publib.boulder.ibm.com/infocenter/ibmxiv/r2/index.jsp

IBM System Storage DS8000® using SDDPCM

IBM System Storage DCS3700 AIX 6.1 and 7.1 with GPFS V3.5 or later, and IBM Storage Scale V4.1 or later

IBM System Storage DS5000 all supported expansion drawer and disk types including SSD This includes models: DS5100, DS5300 and DS5020 Express. on AIX V7.1 with GPFS V3.5 or later, and IBM Storage Scale V4.1 or later on AIX V6.1 with a minimum level of TL2 with SP2 and APAR IZ49639 GPFS V3.5 or later, and IBM Storage Scale V4.1 or later Firmware levels: 7.60.28.00 7.83.22.00 7.77.34.00

IBM System Storage DS3400 (1726-HC4) See http://www-07.ibm.com/storage/includes/pdf/TSD03007USEN.pdf.

IBM TotalStorage ESS (2105-F20 or 2105-800 with SDD)

IBM System Storage Storage Area Network (SAN) Volume Controller (SVC) V2.1 and V3.1 See www.ibm.com/support/docview.wss?rs=591&uid=ssg1S1002471 for specific advice on SAN Volume Controller recommended software levels.

Hitachi Virtual Storage Platform (VSP G200, G400, G600, G800, F400, F600, F800) Hitachi Virtual Storage Platform (VSP G350, G370, G700, G900, F350, F370, F700, F900) Hitachi Virtual Storage Platform (VSP E590, E790, E990, E1090, E590H, E790H, E1090H) Hitachi Virtual Storage Platform (VSP G1000, G1500, F1500) Hitachi Virtual Storage Platform (VSP 5100, 5200, 5500, 5600, 5100H, 5200H, 5500H, 5600H) Note: These tests were conducted on: AIX 7.2 TL03 or later, AIX 7.3 or later IBM Storage Scale V5.0.2.3 or later HDLM V8.7.0 or later, built-in multipath MPIO

Hitachi Universal Storage Platform (USP V) Hitachi Adaptable Modular Storage (AMS)             - AMS Series (includes 2100, 2300 and 2500 models) Note: In all cases Hitachi Dynamic Link Manager™ (HDLM) (multipath software) or MPIO is required. Hitachi Vantara (HV) was previously known as Hitachi Data Systems (HDS). MPIO-ODM packages for AIX supplied by HV are required for all the listed USP V and AMS devices. Customers should consult with HV to verify that their proposed combination of the listed components is supported by HV.

EMC Symmetrix VMAX and DMX Storage Subsystems (FC attach only) Device driver support for Symmetrix includes both MPIO and PowerPath. Selected models of EMC CLARiiON CX/CX-3 family including CX300, CX400, CX500 CX600, CX700 and CX3-20, CX3-40 and CX3-80 Note: CX/CX-3 requires PowerPath. See http://www.emc.com. Customers should consult with EMC to verify that their proposed combination of the above components is supported by EMC.

HP XP 128/1024 HP StorageWorks Enterprise Virtual Arrays (EVA) 4000/6000/8000 and 3000/5000 models that have been upgraded to active-active configurations Note: HDLM multipath software is required HPE 3PAR OS 3.3.1 Minimum Firmware Level: HPE 3PAR OS 3.3.1 RHEL 6.7 with GPFS V4.2.3.4 or later

Table 36. Disk hardware tested with Linux on x86 servers

Hitachi Virtual Storage Platform (VSP) Hitachi Storage Platform (VSP G200,G400,G600,G800, microcode 83-03-24-00/00) Hitachi Virtual Storage Platform (VSP) (F400, F600, F800, microcode 83-03-24-00/00) Hitachi Storage Platform (VSP G1000, VSP G1500, microcode 80-04-22-00/00 or later) Hitachi Unified Storage VM RHEL 7.1 or later, with IBM Storage Scale V4.2.1.1 or later

IBM FlashSystem A9000/A9000R Firmware version 12.0.1 RHEL 7.2 or later, with IBM Storage Scale V4.2.1.0 or later See Q4.12 What are the considerations for using thinly provisioned or compressed volumes with GPFS? for considerations on thin provisioning and compression on these storage subsystems.

IBM FlashSystem 900 Minimal Firmware Level: 1.2.0.11 RHEL 6.5, or later, and SLES 11 SP3, or later, with IBM Storage Scale V4.1.0.8 or later

IBM FlashSystem 840 Minimum Firmware Level: 1.1.1.2 RHEL 6.5 and SLES 11 SP with GPFS V3.5.0.20  or later, and IBM Storage Scale V4.1.0.2 or later

IBM FlashSystem 820 Infinband and FC attach Minimal Firmware Level: 6.3.1.0 RHEL 6.3 or later and SLES 11 SP 1 or later, with GPFS V3.5.0.11 or later RHEL 6.3 or later and SLES 11 SP 2 with IBM Storage Scale V4.1 or later

IBM Flex SystemsStorwize V7000 Firmware Level: SVC 6.4.1.4 RHEL 6.4 or later, and SLES 11 SP2 or later, using multipath Device Mapper GPFS V3.5.0.9  or later, and IBM Storage Scale V4.1 or later RHEL 5.9 and SLES 10 SP4 GPFS V3.5.0.9 or later

IBM Storwize V7000/V3500/V3700/SVC RHEL 6.x and 5.x  with levels of GPFS that support the distribution SLES11 SP2 or later with GPFS V3.5 or later, and IBM Storage Scale V4.1 or later SLES 10 SP1 and SP2 with GPFS V3.5 or later

IBM XIV 2810 Minimum Firmware Level: 10.0.1 RHEL5.1 and greater with GPFS V3.5 or later, and IBM Storage Scale V4.1 or later SLES 10.2 with GPFS V3.5 or later, and IBM Storage Scale V4.1 or later For more information, directions and recommended settings for attachment please refer to the latest Host Attach Guide for Linux located at the IBM XIV Storage System Knowledge Center go to http://publib.boulder.ibm.com/infocenter/ibmxiv/r2/index.jsp

IBM System Storage DS8000

IBM System Storage DS3500/DS5300 RHEL 6.2 or later and SLES 11 SP2 or later with IBM Storage Scale V4.1 or later RHEL 6.x, 5.x with GPFS V3.5 or later SLES 11, 10 with GPFS V3.5 or later Firmware level 7.84.44.00

IBM System Storage DCS3700 RHEL 6.0, 5.6 and 5.5 SLES 11.1, 10.4 and 10.3

IBM System Storage DS5000 all supported expansion drawer and disk types including SSD This include: Models: DS5100, DS5300 and DS5020 Express. Firmware levels: 7.60.28.00 7.83.22.00 7.77.34.00

IBM System Storage DS3400 (1726-HC4)

IBM TotalStorage Enterprise Storage Server® (ESS) models 2105-F20 and 2105-800, with Subsystem Device Driver (SDD)

EMC ScaleIO V2.0 without persistent reserve RHEL 7.1, or later, with IBM Storage Scale V4.2.0.1, or later

EMC Symmetrix Direct Matrix Architecture (DMX) Storage Subsystems 1000 with PowerPath v 3.06 and v 3.07

IBM System Storage Storage Area Network (SAN) Volume Controller (SVC) V2.1 and V3.1 See www.ibm.com/support/docview.wss?rs=591&uid=ssg1S1002471 for specific advice on SAN Volume Controller recommended software levels.

IBM DCS9550 (either FC or SATA drives) FC attach only minimum firmware 3.08b QLogic drivers at 8.01.07 or newer and IBM SAN Surfer V5.0.0 or newer

IBM DCS9900 (either FC or SATA drives) FC attach only

Table 37. Disk hardware tested with Linux on Power

IBM FlashSystem™ 900 Minimal Firmware Level: 1.2.0.11 RHEL 6.5 or later, and SLES 11 SP3 or later, with IBM Storage Scale V4.1.0.8 or later

IBM FlashSystem 840 Minimal Firmware Level: 1.1.1.2 using default DM-MP RHEL 6.4 or later, and SLES 11 SP2 or later GPFS V3.5.0.18 or later, and IBM Storage Scale V4.1 or later

IBM Flex System V7000 Firmware Level: SVC 6.4.1.4, 7.1, 7.2 RHEL 6.4 or later and SLES 11 SP2 or later using multipath Device Mapper IBM Storage Scale V4.1 or later RHEL 5.9 or later, RHEL 6.4 or later, SLES 10 SP4 or later, SLES 11 SP2 or later, using multipath Device Mapper with GPFS V3.5.0.9 or later

IBM Storwize V7000/V3500/V3700/SVC Note: Placing GPFS metadata on thinly provisioned or compressed volumes is not supported. RHEL 6.x and 5.x with levels of GPFS that support the distribution SLES11 SP2 or later, with IBM Storage Scale V4.1 or later SLES 10 SP1 or later, and  SLES11 SP1 or later with GPFS V3.5 or later

IBM System Storage DS3500/DS5300 RHEL 6.2 or later and SLES 11 SP2 or later with IBM Storage Scale V4.1 or later RHEL 6.x, 5.x with GPFS V3.5 or later SLES 11, 10 with GPFS V3.5 or later Firmware level 7.84.44.00

IBM System Storage DCS3700 RHEL 6.0, 5.6 and 5.5   SLES 11.1, 10.4 and 10.3

IBM System Storage DS5000 all supported expansion drawer and disk types including SSD This include: Models: DS5100, DS5300 and DS5020 Express. Firmware levels: 7.60.28.00 7.83.22.00 7.77.34.00

IBM System Storage DS8000

Table 38. Disk hardware tested with IBM Storage Scale for Linux on Z

HDS USPV/VSP/VSP G1000 without persistent reserve

EMC without persistent reserve

IBM DS8000 Series

IBM FlashSystem

IBM Storwize V7000

IBM XIV

IBM SVC

IBM Elastic Storage Server (ESS) V4.5.0

Note: Ensure you are running with the latest firmware levels available. DS4000 is not supported See the question Does IBM Storage Scale for Linux on Z support Direct Attached Storage Devices (DASD)? IBM Storage Scale for Linux on Z is supported with EMC without persistent reserve. Customers should consult with EMC to verify if their proposed solution is supported by EMC.

Q4.2:

What Fibre Channel Switches are qualified for IBM Storage Scale usage and is there a FC Switch support chart available?

A4.2:

There are no special requirements for FC switches used by IBM Storage Scale other than the switch must be supported by AIX or Linux or Windows. For further information see www.storage.ibm.com/ibmsan/index.html

Q4.3:

Can I concurrently access SAN-attached disks from both AIX and Linux (x86 and Power) nodes in my IBM Storage Scale cluster?

A4.3:

While the architecture of IBM Storage Scale would generally allow LUNs to be shared between different operating systems (Linux (x86 and Power), AIX, and Windows), the actual implementation of various OS specific features preclude this from being exploited at the current time. There are differences in how disks are labeled, how partitions are created and managed, and how multi-pathing managers react to error conditions between the various OS such that this support isn't offered in IBM Storage Scale today.

For IBM Storage Scale for Linux on Z, SAN-attached disks can only be accessed from Linux on Z cluster nodes.

Q4.4:

What devices does IBM Storage Scale support with SCSI-3 Persistent Reservations?

A4.4:

The following devices are supported with SCSI-3 Persistent Reservations:

• EMC XtremIO 4.0.10, VMAX 3 Hudson 5977.810.784 and Trinity 5977.932.887 using Native MPIO running AIX 6.1 TL9 SP6, AIX 7.1 TL4 and AIX 7.2 or later, through Fiber Channel connection (IBM Storage Scale V4.1.0.0 or later).
• Hitachi Storage Platform (VSP G1000, G1500, F1500) (microcode 80-04-22-00/00 or later) using default DM-MP on x86 Linux running RHEL 7.1 or later, through Fiber Channel connection (IBM Storage Scale V4.2.1.1 or later).
• Hitachi Storage Platform (VSP 5100, 5200, 5500, 5600, 5100H, 5200H, 5500H, 5600H) using default DM-MP on Power Linux running RHEL 8.1 (Power) or later, through Fiber Channel connection (IBM Storage Scale V5.1.0 or later).
• Hitachi Virtual Storage Platform (VSP G200, G400, G600, G800, F400, F600, F800, G350, G370, G700, G900, F350, F370, F700, F900, E590, E790, E990, E1090, E590H, E790H, E1090H, VSP G1000, G1500, F1500, 5100, 5200, 5500, 5600, 5100H, 5200H, 5500H, 5600H) (for the microcode, refer back to Hitachi Vantara for supported microcode levels), using MPIO and HDLM V8.7.0 or later on AIX 7.2 TL03, AIX 7.3 or later, through Fiber Channel connection (IBM Storage Scale V5.0.2.3 or later).
• DCS3700 (firmware 08.20.12.00) using IBM RDAC driver or the default DM-MP on x86 Linux running RHEL7.2, SLES 11 SP3 (IBM Storage Scale V4.2.0.3 or later)
• IBM FlashSystem A9000/A9000R (firmware version 12.0.1) using default DM-MP on x86 Linux running RHEL7.2, or later through Fiber Channel connection (IBM Storage Scale V4.2.1.0 or later)
• IBM FlashSystem 900 (firmware 1.2.0.11) on x86 Linux running RHEL 6.5, or later, or SLES 11 SP3, or later, through Infiniband or Fiber Channel connection
• IBM FlashSystem 900 (firmware 1.2.0.11) on Power Linux running RHEL 6.5, or later, or SLES 11 SP3, or later, through Infiniband or Fiber Channel connection
• IBM FlashSystem 900 (firmware 1.2.0.11) using default AIX PCM on AIX 7.1.3.16 through Fiber Channel and Infiniband connections (GPFS V4.1.0.8 or later)
• IBM FlashSystem 840 (firmware 1.1.1.2) on x86 Linux running RHEL 6.5, or later, or SLES 11 SP3, or later, through Infiniband or Fiber Channel connection
• IBM FlashSystem 840 (firmware 1.1.1.2) on Power Linux running RHEL 6.5, or later, or SLES 11 SP3, or later, through Infiniband or Fiber Channel connection
• IBM FlashSystem 840 (firmware 1.1.1.2) using default AIX PCM on AIX 6.1.9.0 and AIX 7.1.2.3 through Fiber Channel and Infiniband connections (GPFS V3.5.0.19 or later and IBM Storage Scale V4.1.0.0 or later)
• IBM Storwize V7000 (firmware SVC 7.1.0.3) using default DM-MP on Power Linux running RHEL 6.4, or later, or SLES 11 SP2 (GPFS V3.5.0.16 or later and GPFS V3.4.0.20 or later)
• IBMIBM Flex V7000 (firmware SVC 6.4.1.4) using SDDPCM (2.6.3.2) on AIX 6.1.8 or AIX 7.1.2 (GPFS V3.5.0.16 or later and GPFS V3.4.0.20 or later)
• IBMIBM Flex V7000 (firmware SVC 6.4.1.4) using default DM-MP on Power Linux running RHEL 5.9/6.4 or SLES 10.4/11.2 (GPFS V3.5.0.16 or later and GPFS V3.4.0.20 or later)
• IBMIBM Flex V7000 (firmware SVC 7.1.0.0) using default DM-MO on x86 Linux running RHEL 5.9/6.4 or SLES 10.4/11.2 (GPFS V3.5.0.16 or later and GPFS V3.4.0.20 or later)
• IBM Storwize V7000 (firmware SVC 7.1.0.3) using SDDPCM on AIX 6.1.0 and AIX 7.1.0 through Fiber Channel connection
• IBM FlashSystem 820 (firmware 6.3.1 SP1) using default DM-MP on Power Linux running RHEL 6.3 or SLES 11 SP2 through Infiniband or Fiber Channel connections (GPFS V3.5.0.21 or later, and IBM Storage Scale V4.1.0.4 or later)
• IBM FlashSystem 820 (firmware 6.3.1 SP1) on x86 Linux running RHEL 6.3 or SLES 11 SP2 through Infiniband or Fiber Channel connection (GPFS V3.5.0.21 or later, and IBM Storage Scale V4.1.0.4 or later)
• IBM FlashSystem 820 using default AIX PCM on AIX 6.1.0 and AIX 7.1.0 through Fiber Channel connection (GPFS V3.5.0.21 or later, and IBM Storage Scale V4.1.0.4 or later)
• IBM Storwize V7000/V3500/V3700 (SVC firmware) on x86 Linux running SLES 10 SP4, SLES 11 SP2, RHEL 5.8, or RHEL 6.2
• DS5000 using SDDPCM or the default AIX PCM on AIX
• DS8000 (all 2105 and 2107 models) using SDDPCM or the default AIX PCM on AIX
• DS4000 subsystems using the IBM RDAC driver and AIX MPIO on AIX. (devices.fcp.disk.array.rte or MPIO)
• DS3500 using IBM RDAC driver or the default DM-MP on Linux
• DS4800 using IBM RDAC driver or the default DM-MP on Linux
• DS5020 using IBM RDAC driver or the default DM-MP on Linux
• DS5300 using IBM RDAC driver or the default DM-MP on Linux
• DS8000(2107 models) using IBM SDD driver or the default DM-MP on Linux
• EMC VMAX using EMC PowerPath 5.5 P04 B003 and EMC AIX ODM Package 5.3.0.6.

  Please check EMC PowerLink for support details, and consult EMC to verify that the proposed configuration is supported by EMC. Note: The use of AIX MPIO is also supported in this environment.

• HPE 3PAR (HPE 3PAR OS 3.3.1) using the default DM-MP on x86 Linux running RHEL6.7 (IBM Storage Scale V4.2.3.4 or later)

The most recent versions of the device drivers are always recommended to avoid problems that have been addressed.

Note: For a device to properly offer SCSI-3 Persistent Reservation support for GPFS, it must support SCSI-3 PERSISTENT RESERVE IN with a service action of REPORT CAPABILITIES. The REPORT CAPABILITIES must indicate support for a reservation type of Write Exclusive All Registrants. Contact the disk vendor to determine these capabilities.

Also see the question Are there any requirements for Persistent Reserve support in GPFS ?

Q4.5:

What considerations are there when setting up DM-MP multipath service?

A4.5:

To setup up the DM-MP multipath service, depending on node distribution and storage controller firmware level, you may need to modify the /etc/multipath.conf file to fit your individual storage requirements. A default copy of the multipath.conf file can be copied from the /usr/share/doc directory.

As an example, the following attributes are tested with the IBM products DS3500 (1746), DS5020 (1814), DS4800 (1815), and DS5300 (1818) :

  device {
                vendor                  "IBM"
                product                 "1746"
                getuid_callout          "/sbin/scsi_id -g -u -s /block/%n"
                prio_callout            "/sbin/mpath_prio_rdac /dev/%n"
                features                "0"
                hardware_handler        "1 rdac"
                path_selector           "round-robin 0"
                path_grouping_policy    group_by_prio
                failback                immediate
                rr_weight               uniform
                no_path_retry           fail
                rr_min_io               1000
                path_checker            rdac
        }

Note: In order for GPFS failover to take place, the following steps must be taken:

1. The following parameters must be set:
   • features "0"
   • failback immediate
   • no_path_retry fail
2. The mmnsddiscover -a command must be issued in order for the NSD server to rediscover the disks.

Additionally, see

• The IBM Storage Scale documentation at https://www.ibm.com/docs/en/spectrum-scale
• Please refer to each distribution's multipath document for details. For instance:
  • https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Linux/6/html/DM_Multipath/
  • https://www.suse.com/documentation/sles11/stor_admin/?page=/documentation/sles11/stor_admin/data/bookinfo.html

Q4.6:

Are there any steps that need to be taken before disks are used by IBM Storage Scale on AIX?

A4.6:

Yes. Most of the following specifics are for IBM disks. If you have non-IBM disks, comments below help explain how you would need to adjust the commands that are shown. The lsattr and chdev commands are used for all disk types:

• Set all disks that will be used as NSDs to the no_reserve reservation policy.
  • This may require chdev commands to modify the attributes if they are found not set to no_reserve as the default.
  • The reserve_policy needs to be checked on all nodes with access to the disks even if they are not specially coded as NSD servers.
    • The lsattr -El hdiskX -a reserve_policy command should show no_reserve
    • Issue the chdev -El hdiskx -a reserve_policy=no_reserve command to update if necessary.
• Please note this advice pertains to all disks being used by IBM Storage Scale on AIX, not just disks that will be used in a persistent reserve model.
• If there are any issues with the chdev commands contact AIX support for assistance.

Disks from other manufacturers should have their own unique attributes that similarly controls disk reserves. A specific example is the reserve_lock attribute, which needs to have the value no. The lsattr -El device command would show all the attributes that the device supports, along with the current value of each. If it is not obvious which attribute controls reserves on the disk, contact the manufacturer for that information. The lsattr -R -l device -a attribute command can be used to find out all the legal values for the specified attribute. For example lsattr -R -l hdiskx -a reserve_policy.

Q4.7:

Does IBM Storage Scale support Logical Volumes (LVs) ?

A4.7:

Logical Volumes (LVs) are minimally supported under these conditions:

• The customer must maintain LV availability. IBM Storage Scale does not support the management of the export/import or varying on/off of LVs between nodes.
• Conventional LVs can be used when only attached to a single node as a descOnly disk.
• Starting with GPFS 3.5.0.16, Concurrent Mirrored LVs can be used as descOnly disks.

Q4.8:

Does IBM Storage Scale support AIX raw hdisks (rhdisk) ?

A4.8:

Input to the mmcrnsd command requires the use of the hdisks format, not rhdisks. Internal logic converts the hdisk format to rhdisk.

Q4.9:

Does IBM Storage Scale for Linux on Z support Direct Attached Storage Devices (DASD)?

A4.9:

The DASD device driver provides access to real or emulated Direct Access Storage Devices (DASD) that can be attached to the channel subsystem of an IBM Z. This device driver supports the ECKD (Extended Count Key Data) and FBA (Fixed Block Access) devices.

Note: Prior to IBM Storage Scale V4.2.1, an ECKD device has to have all the same Bus-ID on all NSD server nodes.

To enable the usage of FBA devices, the cluster needs to run IBM Storage Scale V4.2.2 or later.

It is recommended to set the failfast parameter of the DASD device so the device driver immediately returns "failed" for an I/O operation when the last path to a DASD is lost. If the failfast parameter is not set, GPFS might hang until the path to the DASD is restored. See the Device Drivers, Features, and Commands documentation for your Linux distribution.

For more information about the device drivers, features and commands of your Linux platform, see Device Drivers, Features, and Commands.

Q4.10:

Does IBM Storage Scale support 4K disk sectors?

A4.10:

Yes, 4K disk sector support requires IBM Storage Scale V4.1.0.5 or later. The following disk subsystems with 4K sector size have been tested by IBM:

• ECKD disk devices (Linux on Z only)
• IBM FlashSystem 820.
• IBM FlashSystem 840
• IBM FlashSystem 900

Note: Other disk devices may work with IBM Storage Scale, though they have not been tested by IBM. See the question What disk hardware has IBM Storage Scale been tested with?

Q4.11:

What are the considerations for using block storage systems that support thinly provisioned volumes (thin provisioning)?

A4.11:

Block storage uses the following terminology:

Thin provisioning

Thin provisioning is the ability to create a volume without immediately allocating the requested space from the pool of usable space. Blocks are allocated to the volume only as required.

Over-provisioning

Over-provisioning occurs when more space is provisioned from a pool than the total amount of usable space in the pool. This is permissible with thin provisioning as a volume’s space is not reserved from the usable space until it is needed, so the total amount of space that is provisioned to all the volumes can exceed the usable amount.

Note: When a pool is over-provisioned, a volume might not be allocated all of the space that is nominally provisioned if all of the usable space has already been allocated to other volumes.

Full allocation

Full allocation instructs the storage system to immediately provision all of the space that is requested for a volume. Fully allocated volumes eliminate the risk that is associated with over-provisioning such as being unable to allocate provisioned space when requested. This is sometimes called fully provisioned.

Note: Not all storage systems support full allocation.

Thin-provisioned disks are supported only through the IBM RPQ or SCORE process. Additionally, when using a storage system or storage pool that supports thin provisioning, the following conditions need to be satisfied:

• All nodes mounting or playing a management role in the file system should be at least at version 5.0.4, and the file system must be upgraded to file system format version 5.0.4 or later.
• The stanza file must include the following line to add thin disks into the file system:

  thinDiskType={scsi | nvme}

• Thin-provisioned disks must be connected to nodes that are running the Linux operating system.

For more information, see the topic IBM Storage Scale with data reduction storage devices in the IBM Storage Scale: Concepts, Planning, and Installation Guide.

Q4.12:

What are the considerations for using IBM Storage Scale with block storage that supports data reduction features including compression or deduplication?

A4.12:

Note: IBM Storage Scale 5.0.4 has introduced support for data reduction storage devices, so configurations that operate with such devices should upgrade IBM Storage Scale to at least that release. As with thin provisioning, the support needs to go through the RPQ or SCORE process. For more information, see the topic IBM Storage Scale with data reduction storage devices in the IBM Storage Scale: Concepts, Planning, and Installation Guide.

Metadata

It is critical that IBM Storage Scale does not unexpectedly run out of space to write or rewrite metadata due to block-level data reduction features. The system or storage administrator is responsible for allocating volumes in such a way that this cannot happen.

• Volumes that are used for metadata must be fully allocated and not use deduplication.
• Compression is permitted; however, you cannot rely on compression to accommodate more metadata than the usable capacity of the volume (for example, you should assume a compression ratio of 1:1 and allow for any overhead that is incurred by the storage system in managing compression).

Data

Deduplication and compression might be supported after a review by IBM. Ask your sales representative to contact IBM Storage Scale development through the RPQ process.

Q4.13:

How is IBM Storage Scale capacity determined for licensing purposes with thinly provisioned volumes or data reduction?

A4.13:

When using thinly provisioned volumes, the capacity to be licensed is the provisioned capacity presented as NSDs to IBM Storage Scale.

Note: If the storage pool is over-provisioned, the capacity to be licensed might be more than the usable capacity of the pool.

For fully allocated volumes, the provisioned capacity and the usable capacity of the NSD are equal. Data reduction does not affect IBM Storage Scale licensing. While it might increase the effective capacity of the storage system, it does not change the provisioned capacity.

Q4.14:

Does IBM Storage Scale for Linux on Z work with disk hardware replication?

A4.14:

Storage subsystems, such as IBM DS8000, offer data replication mechanisms. For example, Metro Mirror provides synchronous data replication; whereas, Global Mirror provides asynchronous data replication over distance. IBM Storage Scale supports disk hardware replication provided that the disks (FCP LUNs or ECKD volumes) are within a consistency group. The IBM Storage Scale configuration needs to be set up in a way that handles the different device addresses used for primary and secondary devices.

Disk replication can be managed by products such as IBM GDPS® (Geographically Dispersed Parallel Sysplex®) or IBM CSM (Copy Services Manager).

Q4.15:

Does IBM Storage Scale for Linux on Z support HyperSwap or SVC Stretch Clusters?

A4.15:

IBM Storage Scale supports HyperSwap, SVC Stretch Clusters, or similar technologies on IBM Z beginning in IBM Storage Scale V4.2.3.1. The actual swap from one device to another results in a pause to IO while the necessary storage level actions are taken. The failureDetectionTime and leaseRecoveryWait tunables need to be set accordingly. It is suggested to use a value of 1.5X the expected pause time. The user should contact their provider to discuss expected IO pause time for their particular configuration as the actual values depend on the HyperSwap/stretch cluster technology, as well as the storage subsystem and configuration. For more information about HyperSwap with IBM DS8000, see the following white paper: Hyperswaping IBM Spectrum Scale for Linux on z under GDPS Virtual Appliance management control.

Q4.16:

What disk connection technologies can be used for NSD storage?

A4.16:

IBM Storage Scale NSDs can be created on arrays accessed through many different connection technologies including Fibre Channel SAN, SAS, InfiniBand SRP, iSCSI, NVMeOF, and other disk connection technologies.

Q5.1:

What are the IBM Storage Scale cluster size limits?

A5.1:

The current maximum tested IBM Storage Scale cluster size limits are:

Table 39. IBM Storage Scale maximum tested cluster sizes

IBM Storage Scale for Linux (x86, Power, and IBM Z)	9620 nodes
IBM Storage Scale for AIX	1530 nodes
IBM Storage Scale for Windows on x86_64 Architecture	64 Windows nodes
FPO-enabled	732 nodes
IBM Storage Scale for Linux and IBM Storage Scale for AIX	3906 (3794 Linux nodes and 112 AIX nodes)
Note: Contact scale@us.ibm.com if you intend to exceed: Configurations with Linux nodes exceeding 512 nodes. Configurations with AIX nodes exceeding 128 nodes. Configurations with Windows nodes exceeding 64 nodes. FPO-enabled configurations exceeding 32 nodes, see 2.19 What are the current limitations for using the File Placement Optimizer (FPO) function?.

Although IBM Storage Scale is typically targeted for a cluster with multiple nodes, it can also provide high performance benefit for a single node so there is no lower limit. For a given I/O configuration, typically multiple nodes are required to saturate the aggregate file system performance capability. If the aggregate performance of the I/O subsystem is the bottleneck, then IBM Storage Scale can help achieve the aggregate performance even on a single node.

Q5.2:

What are some scaling considerations for the protocol (CES) nodes?

A5.2:

When planning for scaling the protocols function, consider the maximum supported or maximum recommended number of protocol nodes and client connections. For detailed information, see Scaling considerations.

Q5.3:

What is the current maximum tested limit for SMP scaling?

A5.3:

The largest SMP scale tested to date is 192 cores. The largest vCPU (hardware thread) count tested to date is 1536 total vCPUs. The largest NUMA Complexity metric tested to date is 3. The NUMA Complexity metric is the number of different node distances values as reported by numactl --hardware on Linux or REF1 numbers as reported by lssrad -av on AIX. This 1536 vCPU limit is a hard-coded and enforced GPFS limit.

For the following Linux example, the numactl --hardware distinct node distances values are {10; 11}. The NUMA Complexity metric is therefore 2.

node distances:
node  0   1
0:    10  11
1:    11  10

Q5.4:

What is the current limit on the number of nodes that may concurrently join a cluster?

A5.4:

As of GPFS V3.4.0.18 and GPFS V3.5.0.5, the total number of nodes that may concurrently join a cluster is limited to a maximum of 16384 nodes.

A node joins a given cluster if it is:

• A member of the local GPFS cluster (the mmlscluster command output displays the local cluster nodes).
• A node in a different GPFS cluster that is mounting a file system from the local cluster.

For example:

• GPFS clusterA has 2100 member nodes as listed in the mmlscluster command.
• 500 nodes from clusterB are mounting a file system owned by clusterA.

In this example clusterA therefore has 2600 concurrent nodes.

Q5.5:

What is the limit of remote clusters that a client node can join?

A5.5:

The maximum number of remote clusters that a client node can join is 31 (32 when counting the local cluster).

Q5.6:

What is the limit of remote clusters that can join a local cluster?

A5.6:

There is not really a limit. The smallest cluster possible is a single node cluster, which means that 16,383 clusters can join a local cluster (16384 - 1).

Q5.7:

What are the current file system size limits?

A5.7:

The current file system size limits are:

Table 40. Current file system size limits

GPFS 2.3 or later, file system architectural limit	2^99 bytes
GPFS 2.2 file system architectural limit	2^51 bytes (2 Petabytes)

Q5.8:

What is the current limit on the number of mounted file systems in an IBM Storage Scale cluster?

A5.8:

The current limit on the number of mounted file systems in an IBM Storage Scale cluster is 256 on all supported OSs except for Windows. On Windows, the limit is the number of unused drives in the range A-Z.

Q5.9:

What is the architectural limit of the number of files in a file system?

A5.9:

The architectural limit of the number of files in a file system is determined by the file system format:

• For file systems created with GPFS V3.4 or later, the architectural limit is 2⁶⁴.

  The current tested limit is 9,000,000,000.

• For file systems created with GPFS V2.3 or later, the limit is 2,147,483,648.
• For file systems created prior to GPFS V2.3, the limit is 268,435,456.

Please note that the effective limit on the number of files in a file system is usually lower than the architectural limit, and could be adjusted using the mmchfs command (GPFS V3.4 and later use the --inode-limit option).

Q5.10:

What is the architectural limit of the number of disks in a file system?

A5.10:

The architectural limit of the number of disks in a file system is 2048.

Q5.11:

What are the limitations on IBM Storage Scale disk size?

A5.11:

The maximum disk size is only limited by the OS kernel and device driver support

Table 41. Maximum disk size supported

OS kernel	Maximum supported GPFS disk size
AIX, 64-bit kernel	>2TB, up to the device driver limit
Linux 2.6 64-bit kernels	>2TB, up to the device driver limit
Windows	>2TB, up to the device driver limit

Note:

1. On systems running with the Linux kernel 3.0, both processor.max_cstate and intel_idle.max_cstate should be set to zero.
2. IBM Storage Scale supports 16MB file system block size.

Q5.12:

What is the limit on the maximum number of groups a user can be a member of when accessing a GPFS file system?

A5.12:

Each user may be a member of one or more groups, and the list of group IDs (GIDs) that the current user belongs to is a part of the process environment. This list is used when performing access checking during I/O operations. Due to architectural constraints, GPFS code does not access the GID list directly from the process environment (kernel memory), and instead makes a copy of the list, and imposes a limit on the maximum number of GIDs that may be smaller than the corresponding limit in the host operating system. The maximum number of GIDs supported by GPFS depends on the platform and the version of GPFS code. Note that the GID list includes the user primary group and supplemental groups.

Table 42. Maximum number of GIDs supported

Platform	Maximum number of GIDs supported
AIX	2,0481
Linux with 4K page size (all supported platforms except the two below)	1,020
Linux with 64K page size (PPC64/RHEL5/RHEL6/RHEL 7 platforms)	16,380
Windows	Windows OS limit (no limit in GPFS code)

Note:

1. The table reflects the maximum value that can be achieved with IBM Storage Scale 5.0.0 or later and AIX 7.1 or later. On earlier versions of IBM Storage Scale or AIX, the limit is 128. For more information about configuring the Number of Groups allowed, see https://www.ibm.com/support/knowledgecenter/ssw_aix_71/com.ibm.aix.security/number_groups_allowed.htm.