21TB of Storage Avaiable but only 9TB are Available??

[ebartocci]

I have 6 x 4TB hard drives in a RaidZ2 configuration and Freenas shows that I have only have 9TB available to use. I remember when I first setup my system a few years ago that I had around 15 TB of usable space and now that number has been reduced.

I had looked at "https://wintelguy.com/zfs-calc.pl" thinking that I had gone crazy but using the ZFS calculator, also shows that I should have around 15TB of usable storage.

I looked around the forum but I could not find anything that is similar to my issue any help would be greatly appreciated.

Here is a link of the my Freenas dashboard.

Monosnap

Monosnap screenshot tool for Mac and PC with own cloud storage. Take screenshots, record videos and upload files directly to the cloud. Just in one click.

monosnap.com

 

[jgreco]

Snapshots, maybe?

 

[ebartocci]

I only have 3 snapshots and they are taking very little space. See the screenshot below.

Monosnap

Monosnap screenshot tool for Mac and PC with own cloud storage. Take screenshots, record videos and upload files directly to the cloud. Just in one click.

monosnap.com

 

[sretalla]

OK, so I count 6 x 3.6 TiB disks which would be about 3TB each in terms of real storage... RAIDZ2, 34% full pool,

4 disks of effective storage, 12TB minus 34% is about 9TB... nothing missing.

If you use 4000GB in the calc instead of 3600GB per disk, you get to the incorrect number you're thinking about.

 

[ebartocci]

I understand what you are saying. Makes sense with the new numbers.

What about the below, why would the system state that I have 14.26 available capacity after extension?

Monosnap

Monosnap screenshot tool for Mac and PC with own cloud storage. Take screenshots, record videos and upload files directly to the cloud. Just in one click.

monosnap.com

Thanks in advanced for your help.