0016 Refactor backup and restore

Context and Problem Statement

The backup via k8up was not stable, despite some fixed which have been added into k8up.

Should we keep fixing up k8up or change the approach to a different tool?

Considered Options

• Stay with k8up and keep fixing

• Back to volsync again

Decision Outcome

Volsync will be used to backup and restore the cluster.

Due to the improvements and stage splits in the backup and restore there is no pressing need anymore to support the restic tags.

Volsync does use snapshots via the CSI drivers both for the restore and for the backup, this does ensure consistent and reliable backups. The usage of snapshots in restore has already been proven to be valuable in the custom implementation.

There is a possibility that restoring the database clusters will also be possible based on snapshots.