Missing space

I did a fresh install of TrueNAS 13 on a HP Microserver with 16GB RAM, with four 9.1TB drives. I would estimate I should have about 26-27TB, but my pool is only 16TB. I found an option to expand to all available drive space. It seemed to do something, but still only 16GB. Any idea where my 10TB went? More importantly, how do I get it back? Thanks!

results of “zpool status” please

U ran the command in the shell, but couldn’t copy the text. Basically it shows main pool, RAIDZ2-0, and what looks like 4 drives, all online, no errors, running a scrub (Which I started, hoping somehow it might help).
The scrub seems to indicate the full size:
6.45T scanned at 221M/s, 5.99T issued at 205M/s, 34.5T total

While not optimal, even a screenshot of the output is useful.

Forget the “Shell” button in the UI exists and SSH to the server instead–it’s much more reliable.

That explains it–a RAIDZ2 pool will have a total capacity equal to n-2 drives, where n is the total number of drives. Allowing for overhead, slop, and the like, you have exactly the available capacity that would be expected.

Thanks for the help. I didn’t see an option for RAID when creating the pool. How do I change it to a RAID type that will give me 3/4 of the available space?

Destroy the pool and recreate it with the RAID level you want.

You have 10 TB drives that when formatted leaves roughly about 9.1TB free.
Z2 requires 2 drives for parity so based on 10TB drives this would work out to about the following. While your 16TB is a little less it could be because Truenas uses TiB and not TB for size and also there will be some slop and swap space, so the reported size of 16TB is right in the ballpark. For design calculations you should subtract 20% from the calculated usable space for the free space limit (80% max fill).

10TB drive formatted capacity (TiB):9.094947
Raw Storage: 36.25TiB, 39.858TB, 99.64%
Usable Storage: 17.027TiB, 18.721TB, 46.80% space efficiency
z2 minus 20% for free space limit (80% fill max):
Practical usable storage capacity:13.621TiB, 14.980TB, 37.44% eff

RAID-Z2 uses two disks for Parity (double parity) and requires at least four drives to be used.

Z1 (single parity) uses a single drive for parity.
Would raise the usable space to around:
25.540TiB, and 28.081TB, space efficiency increases to about 70.20%
z1 minus 20%for free space limit (80% fill max)
z1 Practical usable storage capacity:20.440TiB, 22.465TB, 56.16% eff

In your case unless you want the safety of z2 it would be better to use z1 with 4 drives.

RAID-Z1 uses one disks for Parity (single parity) and requires at least three drives to be used.

Design/cost calculator:

That sucks, just finished transferring 16TB. Done.

Also, despite changing the hostname and rebooting both the NAS and the computer I’m connecting with, It still shows up as TRUENAS. Is there somewhere I should change this?

Look at system settings/services/smb