Disk size and available space

[ookrisoo]

Hello
I currently have 2 (ada0 an ada1) 2TB disks each. After installing them in the system and configuring them as a mirror, Freenas reports that I have available for use just over 1TB. Where's the rest of the place? Is everything intended for the ZFS file system?

 

[danb35]

Freenas reports that I have available for use just over 1TB.

No, it doesn't. It reports that 765 GiB are used, and 1.1 TiB remain available, exactly as expected.

 

[garm]

FreeNAS counts TiB, not TB used by drive manufacturers. You have 760 odd GiB used and 1.1 TiB available. That is perfectly normal on a 2 TB drive mirror because 2 TB = 1.8 TiB.

 

[danb35]

What's interesting is that this is a fairly-common area of confusion--not so much the TB/TiB issue (which is also common, but not the primary issue here), but that people read "available" as the total space, not the free space. I'm not sure why; it seems perfectly clear to me, but obviously others don't see it that way. This is the first time I've seen it mentioned with Polish (which I presume is the language being used in the GUI screen shot above), though.

 

[ookrisoo]

No, it doesn't. It reports that 765 GiB are used, and 1.1 TiB remain available, exactly as expected.

Thanks.
I did not notice that there is a column "available" and "used". A total noob from me;)

 

[Kevin Horton]

What's interesting is that this is a fairly-common area of confusion--not so much the TB/TiB issue (which is also common, but not the primary issue here), but that people read "available" as the total space, not the free space. I'm not sure why; it seems perfectly clear to me, but obviously others don't see it that way. This is the first time I've seen it mentioned with Polish (which I presume is the language being used in the GUI screen shot above), though.

Would it be clearer if “Free”, or “Unused” were used instead of “Available”?

 

[ookrisoo]

Would it be clearer if “Free”, or “Unused” were used instead of “Available”?

Yes, it is in Polish.
And at first glance, it can lead to misunderstanding.

 

[garm]

"Available" is the term used by ZFS so I dont think it should be changed. English isn't my first language but I do read it as "remaining" space. But I can see where the confusion comes from. I wonder if the ambiguity is worse in translated UIs. In the Swedish UI it translates "Available" and "Used" at least, but I know from work that other EU language struggle with localization. German for instance is a problem with the software I manage professionally. The UI in English uses "delete" and "remove" in vary different ways, but in German they use the same term to translate both...

 

[Erwin]

FreeNAS counts TiB, not TB used by drive manufacturers. You have 760 odd GiB used and 1.1 TiB available. That is perfectly normal on a 2 TB drive mirror because 2 TB = 1.8 TiB.

There is a good calculator available: https://wintelguy.com/zfs-calc.pl
It explains the reasons for all this 'lost' disk space.