monitoring

VirtualMachineInstanceHasEphemeralHotplugVolume

Meaning

The VirtualMachineInstanceHasEphemeralHotplugVolume alert is triggered when a virtual machine instance (VMI) contains an ephemeral hotplug volume. An ephemeral hotplug volume only exists in the VMI and does not persist when restarting a virtual machine (VM).

Impact

The HotplugVolumes feature gate will be deprecated in a future release and will be replaced by the DeclarativeHotplugVolumes feature gate. The two are mutually exclusive, and when DeclarativeHotplugVolumes becomes enabled, any remaining ephemeral hotplug volumes will be automatically unplugged from all VMIs.

This alert is triggered to inform users about the future deprecation and to suggest steps to convert ephermeral volumes to persistent ones.

Diagnosis

1. Find each VM that contains an ephemeral hotplug volume. This command returns a list with entries in the [vm-name, namespace] format.

    $ kubectl get vmis -A -o json | jq -r '.items[].metadata | select(.annotations | has("kubevirt.io/ephemeral-hotplug-volumes")) | [.name , .namespace] | @tsv'
   

2. For each VM listed, find the volumes that need to be patched.

   $ kubectl get vmis <vm-name> -n <namespace> -o json | jq -r '.metadata.annotations."kubevirt.io/ephemeral-hotplug-volumes"'
   

Mitigation

To mitigate the impact of this alert, consider converting the ephemeral hotplug volumes in the VM to persistent volumes instead.

To convert ephemeral volumes to persistent volumes, run the following command:

$ virtctl addvolume <vm-name> --volume-name=<volume-name> --persist

If you cannot resolve the issue, see the following resources:

• OKD Help
• #virtualization Slack channel

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