Many people use BTRFS (or ZFS) snapshots of complete volumes, but with "reflink" this works on per-file basis, too. And the best thing about this: It even works with XFS! As my single SSD cache is XFS formatted, this is a good solution to create space-saving backups/snapshots of a VM, but if you use BTRFS you can use the same method.   Note: If you formatted your XFS disk before Unraid 6.9 (?) your partition hasn't enabled this feature and needs to be re-formatted first.   No