This is very bad for periodic snapshot taking... I have checked $ zpool get all | fgrep feature@filesystem_limits t450s feature@filesystem_limits active local but # zfs snapshot -r t450s@`date -u +%F-%T-%Z` $ zfs get -r snapshot_count,snapshot_limit t450s/SWAP NAME PROPERTY VALUE SOURCE t450s/SWAP snapshot_count 1 local t450s/SWAP snapshot_limit 0 local t450s/SWAP@2021-02-03-19:03:42-UTC snapshot_count - - t450s/SWAP@2021-02-03-19:03:42-UTC snapshot_limit - -
I think you're misunderstanding the feature. From the man page "The limit is not enforced if the user is allowed to change the limit." That means that the limit never affects root. It only matters if you've delegated the snapshot permission. Have you? Here's a demonstration: $ sudo zfs create bar/barf $ sudo zfs set snapshot_limit=2 bar/barf $ sudo zfs allow -u somers snapshot bar/barf $ zfs snapshot bar/barf@1 $ zfs snapshot bar/barf@2 $ zfs snapshot bar/barf@3 cannot create snapshot 'bar/barf': out of space $ sudo zfs snapshot bar/barf@3 Notice that even after the limit was exceeded, root was allowed to take another snapshot.