Missing storage

[Gary Frost]

Hi, I've been reading several threads on missing storage, but none of them (not including parity in calcs) seem to cover my scenario.

I have 6x 3TB drives, with a single volumne in RAID-Z2. The online storage calculator says with this config says I should have 12 TB of usable space (obviously). However what I'm seeing is about 10.5 TiB (1.7 TiB used 8.8 TiB available).

Any assistance in how I can diagnose 'where the missing space' is most gratefully received.

 

[BigDave]

Your volume is showing the exact same total space as my six drive 3TB Vdev

Try this calculator
https://jsfiddle.net/Biduleohm/paq5u7z5/1/embedded/result/

Total RAID space 16.37 TiB (notice it's not TB)

 

[pschatz100]

Don't forget about the conversion from TB (reported for the disks) to TiB (reported for the volumes.) It can be a little confusing. Plus, you lose some available capacity due to ZFS overhead and formatting. Don't worry about it.

 

[Gary Frost]

Your volume is showing the exact same total space as my six drive 3TB Vdev

Try this calculator
https://jsfiddle.net/Biduleohm/paq5u7z5/1/embedded/result/

Total RAID space 16.37 TiB (notice it's not TB)

Thanks, the calculator shows

So I guess it's the classic drives showing TB but freenas showing TiB which is the 'lost data'. 10.91 TiB (12TB) is good, I guess I can throw in a cpl more disks, but also perhaps I should rebuild because I probably don't need 2 parity drives for my media.

Thanks again.