SOLVED Huge size difference beween "Used" (GUI) and "sudo du" (Shell)

[JoHapp]

I am having issues freeing space on our TrueNAS.
1) There is no active snapshot and none visibly existing via GUI
2) There is no recycle bin as far as I am aeare or could see.

GUI: Storage tells me, that "UJZ-Projects" uses 15.24 TiB. (16,75 Terabyte)
Shell: "sudo du -hc --max-depth=1" tells me 3.3T total

I could imagine, that there might be some kind of old snaphots, but i can't see or access any.
Are the numbers in Storage misleading?
Is there a shell command, how I can check snapshots?

 

[Ericloewe]

Is there a shell command, how I can check snapshots?

zfs list -t snapshot

Shell: "sudo du -hc --max-depth=1" tells me 3.3T total

Would that not result in a significantly lower figure for du?

 

[anodos]

You can run the command zfs list -o space to get a space breakdown for USED. man zfsprops will explain what all the counters mean.

 

[anodos]

df -T <path> should give you stats that match up with GUI. At the end of the day, the USED and AVAILABLE counters libzfs dishes out (zfs command, py-libzfs, etc) are obtained via same internal ZFS functions as counters you get via statvfs().

FWIW I use `df -T <path>` all the time to covert paths to datasets when investigating things (because often I need dataset for path as well as counters).

 

[JoHapp]

Hi @Ericloewe Fantastic! That already shows me the way forward!
-> ujz-TrueNas/UJZ-Projects@auto-2021-07-26_06-38 11.9T - 11.9T -

There is some old data under the surface. Now I only need to figure out how to remove it...

Would that not result in a significantly lower figure for du?

Hm, as far as i unterstand, it only limits the shown folderstructure to one level, the total size amount between "sudo du -hc --max-depth=1" and "du -h" seams equal.

 

[JoHapp]

You can run the command zfs list -o space to get a space breakdown for USED. man zfsprops will explain what all the counters mean.

NAME	AVAIL	USED	USEDSNAP	USEDDS	USEDREFRESERV	USEDCHILD
ujz-TrueNas/UJZ-Projects	1.77T	15.2T	11.9T	3.29T	0B	0B

very nice viewoption!

 

[JoHapp]

Now I only need to figure out how to remove it...

Here we go.
zfs destroy ujz-TrueNas/UJZ-Projects@auto-2021-07-26_06-38

 

[anodos]

Here we go.
zfs destroy ujz-TrueNas/UJZ-Projects@auto-2021-07-26_06-38

Depending on pool speed and a variety of factors, it may take a little time for the space to get freed. You can view progress via zpool get freeing ujz-TrueNas