Disabling NUMA

Disabling NUMA

1. To disable NUMA, add numa=off to the kernel line in grub.conf file, for example:
a. For RHEL 6
Edit the kernel line in the /boot/grub/grub.conf file

# vi /boot/grub/grub.conf kernel /vmlinuz-2.6.39-400.215.10.EL ro root=/dev/VolGroup00/LogVol00 numa=off

 

b. For RHEL 7
Edit the kernel line in the file /etc/default/grub

# vi /etc/default/grub GRUB_CMDLINE_LINUX="rd.lvm.lv=rhel_vm-210/root rd.lvm.lv=rhel_vm-210/swap vconsole.font=latarcyrheb-sun16 crashkernel=auto vconsole.keymap=us rhgb quiet numa=off

Also make sure you rebuild the the GRUB configuration file using the command below in case of RHEL/CentOS 7.

# grub2-mkconfig -o /etc/grub2.cfg

2. Reboot the server for the changes to take effect.

# shutdown -r now

Verify

To verify after reboot check the /proc/cmdline file to see the GRUB commandline options used. (Example below is from RHEL 6).

# cat /proc/cmdline ro root=/dev/VolGroup00/LogVol00 numa=off

# numactl -H available: 1 nodes (0) node 0 size: 4195 MB node 0 free: 3304 MB node distances: node 0 0: 10

If NUMA was active, there would be more than one node listed.