Difference in reported storage

[TigerXtrm]

I've got an odd issue in FreeNAS that I don't really understand. As far as I know I followed the volume creation wizard and this setup rolled out. But as you can see there is about 2TB missing and these are not the parity drives (there is a total of 8TB of drives in the system). What is going on here and is this fixable?

 

[joeschmuck]

You have about 4.1TiB of storage left. Without knowing your system configuration it's a bit difficult to answer more. Did you ever use a RAID drive calculator? (See my signature for links) RAW capacity and formatted capacity are very different.

 

[gpsguy]

Last March (2016) you planned to build a system with "WD Red 2TB x 6 in RaidZ2". Is this what you currently have?

If so, the numbers are correct. If you subtract the equivalent of 2 drives for parity, that gives you about 8TB of formatted space. The numbers you see in your picture are in TiB. So, 8TB is about 7.2TiB. If you take used (2.9) + available (4.1), it adds up to 7TiB. The minute difference between total and actual is for overhead, system dataset, etc.

 

[TigerXtrm]

Whoops, yeah I actually forgot what I put in the system lol. Confused myself. You are right, there are 6 x 2TB drives in the system, 2 of which are parity.

Still, I don't understand why the top entry says there is 6.5 TiB available and directly underneath it it says 4.1 TiB. Not to mention one entry says there 4.4TiB used and the other says 2.9TiB used. Shouldn't these logically be the same numbers?

 

[joeschmuck]

I'll be honest with you, I knew the reason for the disparity a long time ago and forgot about it. What matters to me is what I really have available which for you is 4.1TiB. These numbers never seem to make common sense, until you dive into how they are created.

 

[TigerXtrm]

Fair enough. If anyone ever remembers the reason I'll be happy to hear it :)

 

[gpsguy]

The first row is the size of the pool, before parity is subtracted. 12TB = 10.8TiB 4.4TiB + 6.5TiB = 10.9TiB

But why they display used and available on this line, is confusing to most users. It's just best to ignore it.

Still, I don't understand why the top entry says there is 6.5 TiB available and directly underneath it it says 4.1 TiB. Not to mention one entry says there 4.4TiB used and the other says 2.9TiB used. Shouldn't these logically be the same numbers?

 

[TigerXtrm]

Ah, now it makes sense. Thanks!

 

[joeschmuck]

What i also don't like is the use of TB and TiB, it should all base 2, not this marketing garbage of base 10. This adds confusion, I dislike it.