Creation of Snapshot with existing snapshot name and same source volume ID

[tushar1701]

Hi ,

I want to know the expected behavior for the below scenario:-

Scenario:- Creation of Snapshot with existing snapshot name and same source volume ID. Lets suppose I take a snapshot A from volume B at time T1. Thereafter I perform some I/O operations and now after some time at time T2 if user tries to take snapshot again with same snapshot name and same source volume ID then will user get the updated snapshot with all I/O performed at time T2 or will return grpc code ALREADY_EXISTS. OR Snapshot won't be re-created if change existing VolumeSnapshot/VolumeSnapshotContent. Changes can be applied in k8s api-server for this object, but VolumeSnapshot&VolumeSnapshotContent won't be synced as no update event will be sent to sidecar-controller.

In CSI Spec here, how can we implement check for the requested sourceVolumeId and sourceVolumeId of snapshot that has been created.

Please confirm the ideal expected behavior in this case.