Re: ZFS Root size keeps going down after upgrade to 13.2-release

From: Olivier Certner <olivier.freebsd_at_free.fr>
Date: Mon, 21 Aug 2023 13:51:26 UTC
Hi,
 
> There doesn't seem to be anything indicative of that space being used up?

Unfortunately, ZFS only reports in USED for snapshots the space that is *unique* to the corresponding snapshot, but not the space common to several ones of them, which could be freeable if it is not shared with the dataset itself.

Use, e.g., "zfs list -o space <dataset>" to see the amount of space taken by snapshots (USEDSNAP column).

For something more granular, you can also use "zfs get written <snapshot>" to see the amount of new data since the previous snapshot (there is also written@<snapshot>, see zfsprops(7)).

Regards.

-- 
Olivier Certner