The BareMetalHostProfile API allows configuring a host to use the
huge pages feature of the Linux kernel on managed clusters.
Note
Huge pages is a mode of operation of the Linux kernel. With huge pages enabled, the kernel allocates the RAM in bigger chunks, or pages. This allows a KVM (kernel-based virtual machine) and VMs running on it to use the host RAM more efficiently and improves the performance of VMs.
To enable huge pages in a custom bare metal host profile for a managed cluster:
Log in to the local machine where you management
cluster kubeconfig is located and where kubectl is installed.
Note
The management cluster kubeconfig is created automatically
during the last stage of the management cluster bootstrap.
Open for editing or create a new bare metal host profile
under the templates/bm/ directory.
Edit the grubConfig section of the host profile spec using
the example below to configure the kernel boot parameters and
enable huge pages:
spec:
grubConfig:
defaultGrubOptions:
- GRUB_DISABLE_RECOVERY="true"
- GRUB_PRELOAD_MODULES=lvm
- GRUB_TIMEOUT=20
- GRUB_CMDLINE_LINUX_DEFAULT="hugepagesz=1G hugepages=N"
The example configuration above will allocate N huge pages of 1 GB each
on the server boot. The last hugepagesz parameter value is default unless
default_hugepagesz is defined. For details about possible values, see
official Linux kernel documentation.
Add the bare metal host profile to your management cluster:
kubectl --kubeconfig <pathToManagementClusterKubeconfig> -n <projectName> apply -f <pathToBareMetalHostProfileFile>
If required, further modify the host profile:
kubectl --kubeconfig <pathToManagementClusterKubeconfig> -n <projectName> edit baremetalhostprofile <hostProfileName>
Proceed with adding bare metal hosts.