Ok, so I have a big storage pool (with seemingly 8000+ snapshots).
The dashboard info is saying:-
Usable Capacity:
13.08 TiB
Used:
12.46 TiB
Available:
629.34 GiB
So, just over 95% used (and the system is alerting because of this.
But, running a zfs list on the Storage1 pool shows:-
root@R410-truenas:/home/admin# zpool list Storage1
NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT
Storage1 18.2T 11.7T 6.43T - - 2% 64% 1.00x ONLINE /mnt
So, 18.2T with 11.7T used and 6.43T free (64% used).
I’m guessing that the size differentials is due to it being an 8 disk pool with 2 parity drives.
But, I’m concerned that the % used has rocketed up from 80% tp 95% over the last week without me adding much if any data to the drive.
So, snapshots I guess.
The age old question, how do I easily and simply and safely from the command line remove all snapshots over 2 weeks old or so, ensuring I’m not damaging my data. I can run a replication task to punt the files over to the Backend storage array I have connected via the SAS expander…
I just want to tidy up the space to reflect the data I have. (I certainly dont have over 10TB of files in use…
Help a numpty out? 
Ta,
STu.