SOLVED Usable space significantly less than total volume size

[entyrion]

Hi all,

I'm using FreeNAS 9.10 and I'm starting to get warnings that my storage usage is >80% of available space, which is not recommended. I have 6x identical 2TB hard drives with 2 of them as parity for a total theoretical storage of about 4x2TB=8TB remaining. When I check the storage section of my GUI, 1TB seems to be missing. Either the parent volume (which I assume includes the parity space) is 8.8 used +2.1 available = 10.9TB, or the parent dataset (which I assume excludes parity space) is 5.9 used + 1.1 available = 7TB. In both cases this falls significantly short of the ~12TB/8TB that should be available from hardware alone (an average of ~183GB short per HDD). Is this normal behavior, or is there something that I'm missing that might help increase the available space on the existing hardware? Thanks for your time and help!

 

[nightshade00013]

Looks about right to me.

http://wintelguy.com/zfs-calc.pl

 

[danb35]

the parent dataset (which I assume excludes parity space) is 5.9 used + 1.1 available = 7TB. In both cases this falls significantly short of the ~12TB/8TB

You aren't accounting for TB vs. TiB.

 

[entyrion]

Thanks for the quick response and very helpful tool! I suspect you're right and that this is working as intended. One quick note though, from the "view disks" section of the GUI, FreeNAS thinks each HDD is 2.0TB (not ~1.8). Why is that?

 

[danb35]

FreeNAS thinks each HDD is 2.0TB (not ~1.8). Why is that?

Because it is. One TB is 0.909 TiB.

 

[entyrion]

You aren't accounting for TB vs. TiB.

Thanks, I think you just answered my follow-up question. Looks like everything is working normally, no magic space I could free up with the click of a button lol. Looks like I'll probably need to start thinking about my next build. Thanks to all for your quick help!

 

[danb35]

Looks like I'll probably need to start thinking about my next build.

Or just grow your pool. Either add another half-dozen disks, or replace your existing disks with larger ones. Both options are outlined in the manual.