* ``backup_client`` role

  * Previously the backup would run even if pre-backup scripts would

    fail. This is no longer the case, and all pre-backup scripts must

    exit with non-zero exit code in order for backup process to

    kick-in.

  * Old backups are now automatically purged after successful

    backup. This could lead to longer runtimes for entire backup

    process, as well as higher CPU usage.