This document shows you how to enable or disable VM Runtime on Google Distributed Cloud
by either updating the VMRuntime
custom resource or running bmctl
commands.
Before you begin
To enable or disable VM Runtime on GDC, you need access to the following resources and tools:
- Access to Google Distributed Cloud version 1.12.0 (
anthosBareMetalVersion: 1.12.0
) or higher cluster. You can use any cluster type capable of running workloads. If needed, try Google Distributed Cloud on Compute Engine or see the cluster creation overview. - The
bmctl
command-line tool. For more information, see Download and install thebmctl
tool.
Enable VM Runtime on GDC
VM Runtime on GDC is automatically installed in Google Distributed Cloud version 1.10 or higher, but is disabled by default. Before you can run VM resources in your Google Distributed Cloud, you must enable the VM Runtime on GDC.
bmctl
To enable the runtime, use the
bmctl
tool:bmctl enable vmruntime --kubeconfig KUBECONFIG_PATH
Provide the path to the kubeconfig file for your cluster. Google Distributed Cloud generates the kubeconfig file on the admin workstation when you create a cluster. By default, the path is
bmctl-workspace/CLUSTER_NAME/CLUSTER_NAME-kubeconfig
.If VM Runtime on GDC is already enabled, the command returns an error.
Additional settings, such as for emulation or image format, can be configured
by editing the VMRuntime
custom resource.
Custom resource
To enable the runtime, update the VMRuntime
custom resource. This custom
resource is installed by default.
Edit the
VMRuntime
custom resource:kubectl edit vmruntime
Set
enabled:true
in the spec:apiVersion: vm.cluster.gke.io/v1 kind: VMRuntime metadata: name: vmruntime spec: enabled: true # useEmulation defaults to "false" if not set. useEmulation: true # vmImageFormat defaults to "qcow2" if not set. vmImageFormat: qcow2
In the preceding
spec
section, the following values can be set:enabled
: set to true to enable VM Runtime on GDCuseEmulation
: If your node doesn't support hardware virtualization, or you aren't sure, set the value to true. If available, hardware virtualization provides better performance than software emulation. TheuseEmulation
field defaults tofalse
, if it isn't specified.vmImageFormat
: Supports two disk image format values:raw
andqcow2
. If you don't setvmImageFormat
, the VM Runtime on GDC uses theraw
disk image format to create VMs. Theraw
format may provide improved performance overqcow2
, a copy on write format, but may use more disk. For more information about the image formats for your VM, see Disk image file formats in the QEMU documentation.
Save the custom resource in your editor.
Verify that the
VMRuntime
custom resource is enabled:kubectl describe vmruntime vmruntime
The details of the
VMRuntime
custom resource include aStatus
section. VM Runtime on GDC is enabled and working whenVMRuntime.Status.Ready
shows astrue
.
Disable VM Runtime on GDC
When you no longer need to use VM Runtime on GDC, you can disable this feature.
bmctl
To disable the runtime, use the
bmctl
tool:bmctl disable vmruntime --kubeconfig KUBECONFIG_PATH \ --force=true
Provide the path to the kubeconfig file for your cluster and values for the following configuration options:
--force
: Set totrue
to confirm you want to delete existing VM resources. The default value isfalse
.
Custom resource
To disable the runtime, update the VMRuntime
custom resource:
Edit the
VMRuntime
custom resource:kubectl edit vmruntime
Set
enabled:false
in the spec:apiVersion: vm.cluster.gke.io/v1` kind: VMRuntime metadata: name: vmruntime spec: enabled: false useEmulation: true vmImageFormat: qcow2
Save the updated custom resource specification in your editor.
To verify that the
VMRuntime
custom resource is disabled, view the pods that run in thevm-system
namespace:kubectl get pods --namespace vm-system
VM Runtime on GDC is disabled when only the pods that belong to the
vmruntime-controller-manager
deployment are running in the namespace.
Understand the behavior for running VMs
The baremetal.cluster.gke.io/vmrumtime-force-disable
annotation can be used on
VM Runtime on GDC resource to define the behavior when the runtime is
disabled while VMs are running in the cluster.
The following example shows that the value of this annotation is set to false
by default:
// VM runtime yaml file
apiVersion: vm.cluster.gke.io/v1
kind: VMRuntime
metadata:
annotations:
baremetal.cluster.gke.io/vmrumtime-force-disable: "false"
name: vmruntime
[...]
When this annotation is set to false
, VM Runtime on GDC tries
to protect running VMs. Delete all running VMs before the
VM Runtime on GDC is disabled, or specify the --force=true
parameter with the bmctl disable vmruntime
command as shown in the previous
section.
The following table explains what happens to running VMs when this annotation
is set to true
or false
and if you specify the --force=true
parameter or
not:
Cluster state | --force parameter | vmrumtime-force-disable annotation | Behavior |
---|---|---|---|
No VMs | N/A | N/A | Disable VM Runtime on GDC. |
Existing VMs | True | True | Delete all running VMs and the related resources. Disable the VM Runtime on GDC. |
True | False | Delete all running VMs and the related resources. Disable the VM Runtime on GDC. | |
False | True | Prompt to delete running VMs and related resources. When all running VMs have been deleted, disable VM Runtime on GDC. | |
False | False | Don't delete any existing VMs that are running. Don't disable the
VM Runtime on GDC. The bmctl command returns an
error. |
VM Runtime on GDC preflight check
The VM Runtime on GDC preflight check validates a set of
prerequisites on the machine's environment before using
VM Runtime on GDC and VMs. VM creation is blocked if
VM Runtime on GDC preflight check failed. The
VM Runtime on GDC preflight check runs automatically when
spec.enabled
is set to true.
kubectl label nodes NODE_NAME "kubevm.io/VM-SkipSchedule"= --kubeconfig KUBECONFIG_PATH
The VM Runtime on GDC preflight check runs when you perform any of the following operations:
Enable VM Runtime on GDC
Enable VM Runtime on GDC features, such as useEmulation
Upgrade clusters
Remove
kubevm.io/VM-SkipSchedule
label at nodesIndependently create VM Runtime on GDC preflight check object by running the
bmctl check vmruntimepfc --kubeconfig KUBECONFIG_PATH
command or applying aVMRuntimePreflightCheck
YAML manifest.
You can launch VMs when the latest VM Runtime on GDC preflight check succeeds. If the preflight check fails, VM creation is blocked and you get preflight check errors.
Verifying preflight check success
To verify if the preflight checks were successful, run the following commands:
Find the last preflight checks performed:
kubectl get vmruntimepfc -n vm-system --kubeconfig KUBECONFIG_PATH
The output should look like the following sample:
NAME PASS AGE vmruntime-preflight-check-6ee61513-ea5d-4340-9374-90396cac129e false 42s vmruntime-preflight-check-f8d71751-a01c-471e-bab5-3370fc2addd5 true 21s
To find the status of a preflight check, run the following command:
kubectl get vmruntime vmruntime -o yaml --kubeconfig KUBECONFIG_PATH
... preflightCheckSummary: preflightCheckSummary: featureStatuses: CPU: passed: true KVM: passed: true preflightCheckName: vmruntime-preflight-check-f8d71751-a01c-471e-bab5-3370fc2addd5 preflightCheckPassed: true ...
Debug preflight check fails
If the preflight check fails, perform the following steps to debug:
Find the last preflight checks performed.
kubectl get vmruntimepfc -n vm-system
Check the status of that preflight check for details.
kubectl get vmruntimepfc -n vm-system \ vmruntime-preflight-check-6ee61513-ea5d-4340-9374-90396cac129e -o yaml \ --kubeconfig KUBECONFIG_PATH
... status: checks: worker-0--52229ee15841099-22c41577139a7b8c.lab.anthos: passed: false results: - checkName: CPU passed: true - checkName: KVM message: | command terminated with exit code 1 ls: /mnt/dev/kvm: No such file or directory passed: false ...
Fix the issue and run VM Runtime on GDC preflight check again. The following shows an example VMRuntimePreflightCheck YAML manifest:
apiVersion: vm.cluster.gke.io/v1 kind: VMRuntimePreflightCheck metadata: name: vmruntime-preflight-check-manual namespace: vm-system