This morning has been derailed by my server responding to incoming emails with:

452 4.3.1 Insufficient system storage

After the initial surprise (there should be >500GB free!), I learned that #znapzend behaves differently wrt source snapshot cleanup based on whether an *unavailable* destination is enabled or not. Dst disabled? Delete src snapshot per retention policy. Dst enabled? Skip src deletion completely.

~2 months of 15-minutely snapshots take a while get deleted 🤦‍♂️ #sysadmin