Backup all known guest systems included in the specified pool.
-`--prune-backups` `[keep-daily=<N>] [,keep-hourly=<N>] [,keep-last=<N>] [,keep-monthly=<N>] [,keep-weekly=<N>] [,keep-yearly=<N>]` ::
+`--prune-backups` `[keep-all=<1|0>] [,keep-daily=<N>] [,keep-hourly=<N>] [,keep-last=<N>] [,keep-monthly=<N>] [,keep-weekly=<N>] [,keep-yearly=<N>]` ::
Use these retention options instead of those from the storage configuration.