I was just looking around at the snapshots and found this,
# zfs list -t snapshot
NAME USED AVAIL REFER MOUNTPOINT
freenas-boot/ROOT/11.2-RELEASE@2018-12-06-13:24:19 1.73G - 1.73G -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201501212031 7.76M - 7.78M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201505130355 7.77M - 7.79M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201506042008 11.1M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201506162331 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201506232120 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201506292332 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201509022158 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201509282017 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201511040813 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201512121950 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201601181840 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201602031011 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201604150515 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-0a90dd7369b81ac71925bc9d69cb57e0 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-9.10-STABLE-201605021851 10.3M - 10.3M -
freenas-boot/grub@Pre-Upgrade-9.10-STABLE-201605240427 10.3M - 10.3M -
freenas-boot/grub@Pre-Upgrade-9.10-STABLE-201606072003 10.3M - 10.3M -
freenas-boot/grub@Pre-Upgrade-9.10-STABLE-201606270534 10.3M - 10.3M -
freenas-boot/grub@Pre-Upgrade-9.10.1
Is there any reason to keep the older snapshot around? Should I just destroy the old ones?
# zfs list -t snapshot
NAME USED AVAIL REFER MOUNTPOINT
freenas-boot/ROOT/11.2-RELEASE@2018-12-06-13:24:19 1.73G - 1.73G -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201501212031 7.76M - 7.78M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201505130355 7.77M - 7.79M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201506042008 11.1M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201506162331 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201506232120 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201506292332 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201509022158 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201509282017 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201511040813 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201512121950 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201601181840 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201602031011 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-9.3-STABLE-201604150515 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-FreeNAS-0a90dd7369b81ac71925bc9d69cb57e0 11.2M - 11.2M -
freenas-boot/grub@Pre-Upgrade-9.10-STABLE-201605021851 10.3M - 10.3M -
freenas-boot/grub@Pre-Upgrade-9.10-STABLE-201605240427 10.3M - 10.3M -
freenas-boot/grub@Pre-Upgrade-9.10-STABLE-201606072003 10.3M - 10.3M -
freenas-boot/grub@Pre-Upgrade-9.10-STABLE-201606270534 10.3M - 10.3M -
freenas-boot/grub@Pre-Upgrade-9.10.1
Is there any reason to keep the older snapshot around? Should I just destroy the old ones?