HPE Nimble FlexVolume Plugin 3.0 and HPE CSI Driver for Kubernetes

[j_heidelberg]

Hello!

We are running a kubernetes cluster on-premise and have connected our HPE Nimble Storage via "HPE Nimble FlexVolume Plugin 3.0". This setup has been running flawlessly for about 3 years. 
We have now upgraded from kubernetes 1.19 to 1.22 and after the upgrade we had an error when creating new PVC with the "HPE Nimble FlexVolume Plugin 3.0", we could fix the error with a small work-around. 
In a next step we update our servers to Ubuntu LTS 20.04, which is not supported by the "HPE Nimble FlexVolume Plugin 3.0" and is not executable in our test environment. 

We would now like to switch to the "HPE CSI Driver for Kubernetes". Is it possible to run "HPE Nimble FlexVolume Plugin 3.0" and "HPE CSI Driver for Kubernetes" in parallel in the cluster without endangering productive PVCs in the cluster and to migrate the data of the PVC?

Thanks!

[Mahesh202]

Hi j_heidelberg

Running two storage drivers in parallel for the same storage system is not recommended, as it can lead to unpredictable behavior and potential data loss. Therefore, it is not advisable to run "HPE Nimble FlexVolume Plugin 3.0" and "HPE CSI Driver for Kubernetes" in parallel on the same cluster.

To migrate the data of the PVC, you can follow the below steps:

1. Create a new PVC with the "HPE CSI Driver for Kubernetes".
2. Mount both the old and new PVCs to a pod.
3. Use a tool like rsync to copy the data from the old PVC to the new PVC.
4. Unmount the old PVC and mount the new PVC to the pod.
5. Delete the old PVC and associated resources.

This will ensure that the data is migrated safely without any loss. Before proceeding with the migration, it is recommended to take a backup of the data to ensure that the data is not lost during the process.

Hope this helps.!!

Regards
Mahesh.