Tip: Change status of PVC from Released to Available

Symptoms:

    When users delete PVC in Kubernetes, the PV status stays on "Released".  Users would like to recreate the PVC with the same PV but failed. new PVC status always stays on "Pending".

Solution:

   We need to manually clear the status to make it "Available" via below command

 kubectl patch pv  <pv name> -p '{"spec":{"claimRef": null}}'

A few simple Tips on Kubernetes

• Core DNS is deployment and Flannel is DaemonSet
• Persistent Volume (PV)  is not under the namespace
• Persistent Volume Claim(PVC) is under the namespace
• Delete PVC will delete PV automatically by default (Oracle Kubernetes Engine). Change retain policy if necessary
• Drain the node before rebooting worker node
• Both TCP and UDP must be open in the worker node subnet.
• If UDP is open after VMs are up and running, we may need to recreate VMs to let docker daemon to work with new settings