For Linux on Z: Changing the kernel settings

Before starting GPFS, perform the following steps on each Linux on Z node.

On SLES:

1. In the /etc/default/grub file, add the following:

   GRUB_CMDLINE_LINUX_DEFAULT=" hvc_iucv=8 TERM=dumb osamedium=eth instmode=ftp x 
   crashkernel=206M-:103M cio_ignore=all,!ipldev,!condev vmalloc=4096G "
   

2. Run the following command:

   grub2-mkconfig -o /boot/grub2/grub.cfg

3. Reboot the node.

On Red Hat® Enterprise Linux 7:

1. In the /etc/zipl.conf file, add vmalloc=4096G as shown in the following example:

   [defaultboot]
   defaultauto
   prompt=1
   timeout=5
   default=3.10.0-957.el7.s390x
   target=/boot
   [3.10.0-957.el7.s390x]
   image=/boot/vmlinuz-3.10.0-957.el7.s390x
   parameters="root=/dev/mapper/system_vg-root 
   crashkernel=auto rd.dasd=0.0.0201 
   rd.lvm.lv=system_vg/root 
   cio_ignore=all,!condev,!0.0.1000-0.0.1002 
   rd.znet=qeth,0.0.1000,0.0.1001,0.0.1002,layer2=1 
   LANG=en_US.UTF-8 
   vmalloc=4096G"
   ramdisk=/boot/initramfs-3.10.0-957.el7.s390x.img

2. Run the zipl command.
   Note: For information about the zipl command, see the topic about the initial program loader for IBM Z® (-zipl) in Device Drivers, Features, and Commands in the Linux on Z library overview.
3. Reboot the node.

On Red Hat Enterprise Linux 8:

1. Use the grubby utility to add vmalloc=4096G for all boot entries on your node as shown in the following example:

   grubby --update-kernel=ALL --args="vmalloc=4096G"

2. Run the zipl command.
3. Reboot the node.

On Red Hat Enterprise Linux 8.3:

New kernel parameter dfltcc is supported. This parameter configures the zlib hardware support for IBM Z architectures. This must be kept at the default value on. zlib hardware support is enabled by IBM Spectrum Scale if available.

New kernel parameter prot_virt is supported. This parameter enables the hosting of protected virtual machines that are isolated from the hypervisor if the hardware support is present. IBM Spectrum Scale supports this parameter.

On Ubuntu:

1. In the /etc/zipl.conf file, add vmalloc=4096G as shown in the following example:

   [defaultboot]
   default=UBUNTU18.04.1
   target=/boot
   
   [UBUNTU18.04.1]
   target=/boot
   image=/boot/vmlinuz
   parameters="crashkernel=1G-:128M zfcp.allow_lun_scan=0 
   scsi_mod.scsi_logging_level=4605 
   printk.time=1 
   zfcp.dbfsize=100 
   root=/dev/disk/by-path/ccw-0.0.db85-part1 
   vmalloc=4096G"
   ramdisk=/boot/initrd.img
   

2. Run the zipl command.
   Note: For information about the zipl command, see the topic about the initial program loader for IBM Z (-zipl) in Device Drivers, Features, and Commands in the Linux on Z library overview.
3. Reboot the node.