To provide important or required performance improvements for some workloads, you can enable OpenStack huge page support for up to 1 GB per page. Huge pages are requested explicitly by using flavor extra specs or image metadata.

Prerequisites

  • Verify that VMware Integrated OpenStack 5.0 or later is running.

  • Verify that your deployment includes vSphere 6.7 or later.

Procedure

  1. Add a flavor extra spec that requests huge pages with hw and quota properties.
    $ openstack flavor set m1.large --property hw:mem_page_size=large
    $ openstack flavor set m1.large --property quota:memory_reservation_percent=100
    
  2. Create an OpenStack instance with the huge page flavor as in the following example.
    $ openstack server create --flavor m1.large --image ubuntu foobar
    
  3. Log in to the guest OS on the VMware Integrated OpenStack console.

    Enabling huge pages is different for every OS. The following example shows how to enable persistent huge pages on a Linux host.

    1. To allocate huge pages at run time, modify /etc/default/grub to include some huge page parameters.
      echo 'GRUB_CMDLINE_LINUX="default_hugepagesz=1G hugepagesz=1G hugepages=2 transparent_hugepage=never"' > /etc/default/grub
    2. Update the bootloader.
      update-grub2
    3. Reboot the instance.
    4. Check that the instance is using huge pages.
      grep "Huge" /proc/meminfo

      The value for Hugepagesize should be 1 GB or less.