Edit

Share via

CSN storage pod container stuck in ContainerCreating

  • Article

This document details user experience of a rare issue that may render CSN storage pods in ContainerCreating state. It also provides a workaround to resolve the issue.

Cause

A runtime-upgrade replaces the operating system of the Baremetal nodes, which recreates the IQN (iSCSI Qualified Name) and can cause iscsi login failure in rare occasions. The iscsi failure occurs on particular nodes where portals login isn't successful. This guide provides a solution for this particular issue.

The guide briefly lays down the process to delete Volumeattachment and restart the pod to resolve the issue.

Process

Check to see why the pod remains in ContainerCreating state:

Warning FailedMapVolume 52s (x19 over 23m) kubelet MapVolume.SetUpDevice failed for volume "pvc-b38dcc54-5e57-435a-88a0-f91eac594e18" : rpc error: code = Internal desc = required at least 2 portals but found 0 portals

Here we focus only on baremetal_machine where the issue has occurred.

Execute the following run command to solve the issue of pod stuck in containerCreating

az networkcloud baremetalmachine run-command --bare-metal-machine-name <control-plane-baremetal-machine> \
--subscription <subscription> \
--resource-group <cluster-managed-resource-group> \
--limit-time-seconds 60 \
--script "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"

The run command executes the following script.

pods=$(kubectl get pods -n nc-system |grep -i containercreating | awk '{print $1}')

for podname in $pods; do
    kubectl describe po $podname -n nc-system

    pvcname=$(kubectl get po $podname -n nc-system -o json | jq -r '.spec.volumes[0].persistentVolumeClaim.claimName')

    pvname=$(kubectl get pvc $pvcname -n nc-system -o json | jq -r '.spec.volumeName')

    nodename=$(kubectl get po $podname -n nc-system -ojson | jq -r '.spec.nodeName')

    volattachName=$(kubectl get volumeattachment | grep -i $pvname | awk '{print $1}')

    kubectl delete volumeattachment $volattachName

    kubectl cordon $nodename -n nc-system;kubectl delete po -n nc-system $podname
done

The command retrieves the pvc from the pod and then deletes the volumeattachment object. It then deletes the pod. The pod later gets recreated on another node along with a successful volume attachment object.

If you still have questions, contact support. For more information about Support plans, see Azure Support plans.