Creating CSI snapshots
Available since Kubernetes 1.20, Volume Snapshots work with your storage provider to create snapshots of your volumes. If you're using a managed Kubernetes provider, you probably already have snapshot support, but if you're a bare-metal cave-monkey using snapshot-capable storage provider (like Rook Ceph), you need to jump through some hoops to enable support.
K8s-sig-storage publishes external-snapshotter, which talks to your CSI providers, and manages the creation / update / deletion of snapshots.
Why do I care about snapshots?
If you've got persistent data you care about in your cluster, you probably care enough to back it up. Although you don't need snapshot support for backups, having a local snapshot managed by your backup tool can rapidly reduce the time taken to restore from a failed upgrade, accidental deletion, etc.
There are two components required in order to bring snapshot-taking powerz to your bare-metal cluster, detailed below: