For Linux on z Systems: Changing the kernel settings

In order for GPFS™ to run on Linux on z Systems™, the kernel settings need to be changed.

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

On SLES 12:

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 "

Run the following command:
```
grub2-mkconfig -o /boot/grub2/grub.cfg
```
Reboot the node.

On SLES11 and Red Hat Enterprise Linux:

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

(10:25:41) dvtc1a:~ # cat /etc/zipl.conf
# Modified by YaST2. Last modification on Mon May 19 09:39:04 EDT 2014
[defaultboot]
defaultmenu = menu

###Don't change this comment - YaST2 identifier: Original name: linux###
[SLES11_SP3_2]
    image = /boot/image-3.0.101-0.15-default
    target = /boot/zipl
    ramdisk = /boot/initrd-3.0.101-0.15-default,0x2000000
    parameters = "root=/dev/mapper/mpatha_part2 hvc_iucv=8 TERM=dumb 
 resume=/dev/mapper/mpatha_part1 crashkernel=258M-:129M vmalloc=4096G
user_mode=home"

Note: For SUSE Linux Enterprise Server (SLES) 11 and Red Hat Enterprise Linux 6, user_mode=home is optional. For Red Hat Enterprise Linux 7.1 and later releases, this parameter is not required.

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

Note: For more detailed information about installation and startup of GPFS on z Systems, see the "Getting started with Elastic Storage for Linux on z Systems based on GPFS technology" white paper, available on the Welcome Page for IBM Spectrum Scale™ in IBM® Knowledge Center.