[Public]
   path = /usr/data/samba/public
   public = yes
   writable = yes
   vfs objects = shadow_copy2
   shadow: snapdir = .zfs/snapshot
   shadow: sort = desc
   shadow: format = %Y-%m-%d_%H.%M.%S--1m

Задание cron для создания снепшотов:

0,30    7-20    *    *   *    root    /usr/local/sbin/zfSnap -d -z -R -a 1m zpool/usr/data/samba/public