zfs snapshot sort by size

When you see your zpool exploding, but the “used” size isn’t that much, you may take a look at your snaphosts.

First find the dataset with the that has the largest snapshot

zfs list -o name,usedbysnapshots | sort -r -k2

example output

tank/mails 56.3G
tank/store 261M
tank/docker 2.38M

In this case the tank/mails dataset should be looked at.

Snapshots can then be listed for that filesystem by using a command

# zfs list -t snapshot -r
zfs list -t snapshot -r tank/mails