Newly created RaidZ2 missing about 4 TB?

[Sander Jansen]

Hey, i mede a new RaidZ2 with 12X2TB disks and there are a few things i dont get...

When i click on storage and get the volume overnieuw it shows:

Name:---------------Used:---------Avalible:
Raid6----------------778.5GB-----21.0TB
---Raid6-------------593.0GB-----15.5TB

The disks i placed should be 24TB and with the raid 6 you lose 2 so that should be 20TB so how can it be that the first line of Raid 6 showes 21 TB? and then the difference between the 21TB and the 15.5 TB ... how did i lose 3.5TB? and in total 5.5TB betwean the 15.5 TB and the 21 TB...

I guess some goes to swap but when i look at the swap, its just 20GB and i dont think its 20 GB per disk? even then it wont sum up... if i do calculations that 15.5 TB should be somewhere around 17 a 18 TB... after format... or am i missing something?

 

[Bidule0hm]

Please read this post ;)

There's also some ZFS overhead and the TB/TiB conversion ratio.

 

[mattbbpl]

Please read this post ;)

There's also some ZFS overhead and the TB/TiB conversion ratio.

You are always on top of the responses to these questions. I feel like you should explore automating responses to them with a script similar to that guy who wrote scripts to automate his coffee retrieval and automatically respond to repetitive emails.

 

[Sander Jansen]

Now i feel so stupid... i have known the difference between TiB and TB... just overlooked it... thanks anyway... im glad everything is fine after all. :)

 

[Bidule0hm]

You are always on top of the responses to these questions. I feel like you should explore automating responses to them with a script similar to that guy who wrote scripts to automate his coffee retrieval and automatically respond to repetitive emails.

If only I could do that... well in theory I can but it would be far too complex for the benefits :D

 

[Sander Jansen]

is it normal that the avalible space slowly goes down? im copying all my data back and its gone down from 21TiB and 15.5TiB to 18.9TiB and 13.8TiB... is this because compression levels? because compression level is around 1.02x?

Never mind... i was not counting the fact it already used some space... im mixing up the available space with total space... dont mind me -.-.....