NFS server IP address changes - what should I do ?

[jackchuong]

Hi all,
I deployed nfs-subdir-external-provisioner using helm to handle storage in a internal k8s cluster , NFS server is a QNAP device.
I need to change IP address of QNAP device, here my values yaml

nfs:
  server: "192.168.0.108"

I didn't use FQDN for server (my mistake) , what should I do if I need to change nfs server IP address to another ?
If I change it and upgrade helm chart, would it work ? What happen with existed PVC and PV ?
I don't want my data to be lost or corrupted. Please give me some advice, thank you very much.

[klaernie]

My recommendation would be for you to first upgrade using the new value and deploy a test pvc to ensure you made no typos and that the hostname you then use is actually working. This however won't touch your existing PVs, so you'll need to kubectl edit each of them and update the spec.nfs.server - or apply a patch with kubectl patch.

Just as an additional tip: if your old and new address are both equally reachable from your cluster I'd recommend you first add the new IP to the NFS server, patch the PVs, reboot your nodes to ensure they have the old NFS server not mounted anymore, and only then remove the old IP from your NFS server. Else you might run into the issue that your nodes trip up on the no longer reachable NFS server.