Snapshot "preserved by system", no space to make new snapshots

Synology
,
1

I have snapshot replication running between my active and backup NASes. Snapshot Replication is running on a volume that’s ~47TB of data. The backup NAS is basically full (I know) so replication tasks just run until they fail essentially, no new successful snapshots. I cleared off about 4TB from the active NAS, but I believe there’s one snapshot left that is holding that deleted data. When I go to the snapshot list to manually remove it, it gives the error “Failed to delete snapshot, preserved by the system”. I’m assuming it won’t delete this snapshot until there’s a new full snapshot, but I can’t make a new snapshot until I delete this old one. Catch 22 or whatever.

Any ideas? I’d like to not delete this Replication task, since it’ll take so long to replicate a new one, this is live data my company is using for clients. It’s worth noting I am also running Hyperbackup to a third NAS, so I’m not super concerned, but would like to do this as efficiently as possible.
Thanks

2

Unfortunately the only way you are going to be able to solve this is to either:

  1. Blow away and rebuild the snapshot task
  2. clear up enough old snapshots from the target that they exist

The reserved snapshot is the most recent snapshot between the two systems thats used for the deltas. If you delete it, you would have to rend over the entire backup again

2 Likes