GitHubContribute in GitHub: Edit online

Known limitations

Before you use Wazi as a Service, make sure that you are aware of the following known limitations.

Limitations of Wazi Image Builder and z/OS custom images

Following are the known limitations of Wazi Image Builder and z/OS custom images.

  • When using z/OS Extraction Utilities, specifically feucvoli, to find data sets from source environments for extraction, uncataloged data sets are not automatically detected and included. In cases where uncataloged data sets are needed, such as JES2 Checkpoint or JES2 spool, the disk volumes containing these data sets must be included manually, unless there are other cataloged data sets on these volumes that have already been identified. If additional volumes that contain uncataloged data sets are needed, the system programmer of the z/OS source environments must make necessary adjustments to the list of volumes.

  • Cloud-init is not enabled in z/OS Wazi aaS custom images.

  • You cannot validate the checksum of the custom images that are deployed from Wazi Image Builder.

  • Cross-region bucket is not supported for custom image deployments. You need to upload to a regional bucket.

  • The zOS-cloud-prepare tool does not support the syntax of substringing system symbols.

Limitations of IBM Cloud VPC and z/OS virtual server instances

Following are the known limitations of z/OS virtual server instances in the IBM Cloud Virtual Private Cloud (VPC).

  • Deleting a subnet through the user interface might not work as expected when you delete an existing VPC. You can use the command ibmcloud is subnet-delete as the workaround.

  • IBM z Systems Integrated Information Processor (zIIP) is not supported, and vCPUs for z/OS virtual server instances are general-purpose processors only.

  • Only the following device types are supported on the z/OS virtual server instances:

    • 3270-X
    • 3279
    • 3390B
    • Open Systems Adapter (OSA)

  • When you create a z/OS virtual server instance, User data parameters are not processed by the z/OS operating system.

  • Removing block storage from a z/OS virtual server instance that is not fully initialized results in the instance failure. The instance cannot be recovered after this type of failure.

  • Accessing your z/OS virtual server instance by using a VNC console on the IBM Cloud UI is not supported.

  • You must store your data in an attached block storage device or volume because updating a z/OS virtual server instance dynamically is not supported. To update your z/OS virtual server instance, use one of the following alternatives:

    • Create an instance with the new version of the z/OS stock image, and then attach the block storage.
    • Create a custom z/OS image with the new fix in your on-premises environment, import the image, and then attach the block storage.

  • The reports generated in the IBM Sub-Capacity Reporting Tool (SCRT) are not valid.

  • z/OS Resource Measurement Facility (RMF) Data Gatherer for SMF record types 70 - 79 has the following restrictions:

    • CPU information
      • SMF record type 70 subtype 1 contains one physical and one logical CPU (similarly as for z/VM systems with enabled VMGUEST option). Postprocessor CPU Activity report is impacted.
      • Monitor III measurement table ERBCPCDB consists of Header Section and Home LPAR section only. Monitor III CPC Capacity report is impacted.
    • Logical Control Unit (LCU) is not supported
      • SMF record type 74 subtype 1 does not contain LCU data. Postprocessor Device Activity report is impacted.
      • SMF record type 78 subtype 3 cannot be gathered due to missing LCU data. Postprocessor I/O Queuing Activity report is impacted.
      • SMF record type 79 subtype 14 cannot be gathered due to missing LCU data. Monitor II I/O Queuing Activity report is impacted.
      • Monitor III measurement table IQDG3 cannot be gathered due to missing LCU data. Monitor III I/O Queuing report is impacted and shows message No hardware data.
    • Retrieval of Crypto Measurement data and Crypto Domain Measurement data is not supported
      • SMF record type 70 subtype 2 does not contain crypto card information. Postprocessor Crypto Hardware Activity report is impacted.
      • Monitor III measurement table CRYG3 does not exist. Monitor III Crypto reports CRYACC, CRYOVW, and CRYPKC are impacted.
    • Dynamic CHPID Management (DCM) is not supported
      • SMF record type 73 contains indicator SMF73CMH (Bit 0 of SMF73SFL) with meaning DCM supported by hardware. This indicator will be OFF. Postprocessor Channel Path Activity is impacted.
      • SMF record type 79 subtype 12 contains indicator SMF79CCMH (Bit 2 of SMF79CFLG1) with meaning DCM supported by hardware. The indicator will be OFF. Monitor II Channel Path Activity report is impacted.
      • Monitor III measurement table CPDG3 contains indicator CPDCMH (Bit 4 of CPDFlg) with meaning DCM supported by hardware. This indicator will be OFF. Monitor III Channel Path Activity report is impacted.
    • Interrupt Delay Time facility is not supported
      • SMF record type 79 subtype 9 contains indicator R799FID (Bit 7 of R799CNX) with meaning Interrupt Delay Time facility is provided. This indicator will be OFF. Hence the Interrupt Delay Time stored in field SMF79IDT will be zero. Monitor II DEV and DEVV reports are impacted.
      • SMF record type 74 subtype 1 contains indicator R74FID (Bit 3 of SMF74ENF) with meaning Interrupt Delay Time facility is provided. This indicator will be OFF. Therefore, the Interrupt Delay Time stored in field SMF74IDT will be zero. Postprocessor Device Activity report is impacted (AVG INT DLY is missing).
    • Utility string facility is not supported
      • SMF record type 73 contains indicator SMF73PNI (Bit 7 of SMF73FG4) with meaning PNET ID SMF73NT1 and SMF73NT2 are valid. This indicator will be OFF. Hence PNET IDs SMF73NT1 and SMF73NT2 will be zero. Postprocessor Channel Path Activity report is impacted.
      • SMF record type 74 subtype 9 contains indicator R749PNVA (Bit 0 of R749FLAG) with meaning PNET ID R749NET1 and R749NET2 are valid. This indicator will be OFF. Therefore, PNET IDs R749NET1 and R749NET2 will be zero. Postprocessor PCIe Activity report is impacted.
      • Monitor III measurement table CPDG3 contains indicator CPDUSF (Bit 6 of CPDCFLG) with meaning Channel path data utility string failure. This indicator will be ON. For this reason, PNET IDs CPDPnetID1 and CPDPnetID2 will be zero. Monitor III Channel Path Activity report is impacted.
      • Monitor III measurement table PCIG3 contains indicator PCINetIDVal (Bit 0 of PCIValidFlag) with meaning PNET IDs are valid. This indicator will be OFF. PNET IDs PCIPnetID1 and PCIPnetID2 will be zero. Monitor III PCIe Activity report is impacted.
    • EADM compression measurement facility is not supported
      • SMF record type 74 subtype 10 and Monitor III measurement table SCMG3 cannot be gathered. Postprocessor and Monitor III EADM Activity reports are impacted.
    • Channel Path Measurement Facility (CPMF) is not supported
      • SMF record type 73 contains indicator SMF73CMF (Bit 5 of SMF73CFL) with meaning CPMF is available. This indicator will be OFF. Postprocessor Channel Path Activity report is impacted.
      • SMF record type 79 subtype 12 contains indicator R79CCPMF (Bit 0 of SMF79CFLG1) with meaning CPMF is available. This indicator will be OFF. Monitor II Channel Path Activity report is impacted.
      • Monitor III measurement table CPDG3 contains indicator CPDCPMF (Bit 2 of CPDFlg) with meaning CPMF is available. This indicator will be OFF. Monitor III Channel Path Activity report is impacted.
    • LIST DATA interface IDCSS01 does not return data
      • SMF record type 74 subtype 5 contains fields R745CSC and R745CRTN, which show the error information and return code of the IDCSS01 interface. Postprocessor Cache Subsystem Activity report is impacted.
      • Monitor III measurement table CATG3 contains fields CATG3_Stat_Code and CTAG3_RC_IDCSS, which show the error information and return code of the IDCSS01 interface. Monitor III Cache Detail and Monitor III Cache Summary reports are impacted.

  • Only one network interface is supported in each z/OS virtual server instance.

  • The Central Processor Assist for Cryptographic Function (CPACF) only supports clear keys in z/OS stock images. Protected keys and secure keys are not supported.

  • PCIe cards such as the Cryptographic Coprocessor, Acceleration, and Compression are not supported.

  • Disks are not available to share between z/OS virtual server instances.

  • The multisystem sysplex (MULTISYSTEM) is not supported and the system must be either in a single-system sysplex (MONOPLEX) or in XCF-local mode. You can use a system IPL parameter PLEXCFG=(MONOPLEX,XCFLOCAL) in the IEASYSxx parmlib member, which enables the system to come up in XCF-local mode when MONOPLEX mode is failed due to issues with the sysplex couple data sets (CDS). For more information, see PLEXCFG External link icon.

  • The only supported GRS specification is GRS = NONE in the IEASYSxx parmlib member, which means that the system is not in a global resource serialization complex.

  • The Coupling Facility Resource Management (CFRM) policy and its related couple data sets (CDS) must not be used because the coupling facilities are not supported. You cannot use the COUPLExx parmlib member to define the type for couple data set in the CFRM. For example, you must not issue SETXCF COUPLE, TYPE=CFRM.

  • z/OS Container Extensions (zCX) is not supported and restricted for use. zCX is not intended for this environment.

  • HWNAME, LPARNAME, and VMUSERID in the IEASYMxx parmlib member or in LOADxx member are not supported.

  • The percentage bar graph might indicate that the memory is fully consumed. This percentage represents the full allocation of memory that is reserved for z/OS, rather than the actual memory usage within z/OS.

For other known limitations of IBM Cloud VPC, see Service limitations External link icon.