Sounds good - thanks again for working on this!

11.3 PR: https://github.com/freenas/ports/pull/558

Windows needs a timestamp tag for each element in the array of snapshots for "previous versions" to work. We can either do a hack based on directory names (which is generally faster, but imposes significant limitations on your naming schemas) or we can get this metadata from ZFS (which is somewhat slower). Using ZFS for this gives us advantages though that weren't possible with the old module. For instance, we can now exclude irrelevant snapshots.

Performance improvements for the actual listing of snapshots will be somewhat harder to come by. In the course of investigation, I noticed though that Windows queries the snapshot list twice. This means that I might be able to reduce the snapshot list generation time for the Windows UI significantly caching the results of that particular FSCTL.

Confirming this fixed it in my setup (Previous Versions took a while to populate - on a HDD mirror - maybe due to more snapshots showing - perhaps a future performance fix - thanks - looking fwd to 11.3U1 !

Create a backup copy of /usr/local/lib/shared-modules/vfs/shadow_copy_zfs.so, replace the original with the copy I uploaded, and then run the command "service smbd onerestart".