CSI Volume Features Support

Starting from Bacula Enterprise version 12.6 and Kubernetes plugin version 2.0, support for Kubernetes CSI Volume Cloning functionality was introduced, along with various other features. Subsequently, in Kubernetes plugin version 2.1 Kubernetes CSI Volume Snapshot functionality was included. The plugin now automatically detects its ability to perform this functionality starting from this version. As of version 2.2, users have the option to select the backup mode that suits their needs while ensuring compatibility.

Starting from version 2.1, users can use CSI Volume Cloning or CSI Volume Snapshot to acquire a consistent data view of selected Volumes.

Additionally, you can configure remote command execution on a selected Container of the Pod. This command execution can be configured just before or after a Pod backup and just after volume snapshot/clone creation. More details in here.

CSI drivers may or may not have implemented the volume cloning or snapshot functionality. The reference to clone feature is CSI Volume Cloning. The reference to snapshot feature is Volume Snapshots.

The main distinction between CSI Volume Cloning and CSI Volume Snapshot is that Volume Cloning creates an exact duplicate of the specified volume, meanwhile, the Volume Snapshot represents a point-in-time copy of a volume. Therefore, a snapshot-based backup offers greater consistency.

When performing persistent volume backups, our plugin uses the volume clone and snapshot api. Given the higher level of consistency associated with snapshotting, our plugin uses this technique by default as long as it is supported by the persistent volume CSI driver.