Use configmaps to set:

• service settings
  • Requires a restart_all_services interrupt
  • Or a restart of the service changed
• ulimit settings
  • No interrupt required
• container limit settings (ulimits as seen by containers)
  • requires a reboot interrupt
• grub configuration
  • requires a reboot interrupt

All changes are made via a drop-in file so they can be uninstalled later without conflicts with other things that might alter the same setting.

Supported configmaps

• grub.conf - This will be used to set grub. The format is one line per argumennt which are turned into space separated values for GRUB_CMDLINE_LINUX_DEFAULT. Suggested to use a reboot so changes are applied
• sysctl.conf - This will be set into /etc/systctl.d. Suggested to use a reboot or restart_all_services to ensure changes are picked up
• ulimit.conf - This set a drop in file in /etc/security/limits.d. It also can call ulimit directly for the following values:
  • memlock
  • nofile
  • fsize
  • stack
  • nproc
• service_{service name}.conf - This will make a drop-in file in /etc/systemd/system/{service name}.service.d. Suggested to use a service restart for this service. systemctl daemon-reload is called for you if any are set.

Special service config files

If you use service_containerd.conf or service_crio.conf post-interrupt check will do a further validation on the settings. If the following lines are in your configmap:

• LimitNOFILE
• LimitFSIZE
• LimitSTACK
• LimitNPROC
• LimitMEMLOCK It will use ulimit to check that the expected value is actually set. Note: for LimitSTACK and LimitMEMLOCK it compares against expected_value/1024 due to formatting output of the ulimit call.

Example NodeWright Custom Resource

Update grub and sysctl. Use main reboot interrupt for the first apply. Specify different interrupts for the configmap interrupts to apply a more limited one depending on which one changes.

tuning:
    version: 1.1.4
    image: ghcr.io/nvidia/skyhook-packages/tuning
    interrupt:
        type: reboot
    configInterrupts:
        grub.conf:
            type: reboot
        sysctl.conf:
            type: restart_all_services
    configMap:
        grub.conf: |-
            hugepagesz=1G
            hugepages=2
            hugepagesz=2M
            hugepages=5128
        sysctl.conf: |-
            fs.inotify.max_user_instances=65535
            fs.inotify.max_user_watches=524288
            kernel.threads-max=16512444
            vm.max_map_count=262144
            vm.min_free_kbytes=65536
        ulimit.conf: |-
            memlock=128
            fsize=1000

Update just sysctl

tuning:
    version: 1.1.4
    image: ghcr.io/nvidia/skyhook-packages/tuning
    interrupt:
        type: restart_all_services
    configMap:
        sysctl.conf: |-
            fs.inotify.max_user_instances=65535
            fs.inotify.max_user_watches=524288
            kernel.threads-max=16512444
            vm.max_map_count=262144
            vm.min_free_kbytes=65536

Update containerd stack size

tuning:
    version: 1.1.4
    image: ghcr.io/nvidia/skyhook-packages/tuning
    interrupt:
        type: service
        services:
            - containerd
    configMap:
        service_containerd.conf: |-
            [Service]
            LimitSTACK=67108864
            LimitMEMLOCK=infinity