Dataset size smaller after drive replacement

[lyzard]

I run a FreeNAS with four 4TB drives in a ZRAID1 config. It has an encrypted volume called MainVol. Under it is a dataset called MainVol also. In hindsight, I probably should've given them less confusing names. Under the MainVol dataset, I have two datasets, Storage and Movies, that I use to configure permissions for my similarly named two Windows shares. I recently replaced ada0 with an identical 4TB drive. The drive wasn't failing, I just wanted to go through the process. I followed the steps on the user guide for replacing an encrypted drive and everything worked fine. I still have access to my data and my shares work as before. However, now the size of the MainVol dataset is one drive smaller than the size of the MainVol volume. Do I need to expand the dataset to fill the entire volume? How would I do that? Or is there something wrong with this configuration that would cause this problem?

Thanks,
L

 

[DrKK]

A few things:

It is normal to see "MainVol" and then right below it "MainVol". Confusing, I know. BUt this is how we do it apparently. The first "MainVol" is indicative of your pool/volume. When you highlight that one, you will get "pool" level buttons on the bottom, like, "detach", or "scrub", or "status". The second, slightly indented one, is the root dataset that goes with that pool. When you highlight that one, you'll get dataset level buttons showing up, like Snapshot, or set permissions, or whatever. So that wasn't you, that's how the GUI works.

As for the weird size issue you have, that sounds like a bug/weirdness to me. just verify that zpool status -v at the command line shows the expected number of drives, and then, I would imagine a reboot should solve the GUI confusion. If not, then you have located a strange bug that I can't imagine has passed us by for all these years.

 

[lyzard]

Thanks for the fast reply. So the MainVol is the root dataset that's created automatically with the pool? I thought I wouldn't name them the same way, but honestly couldn't remember.

Anyway, the weirdness continues. I restarted but the size between the pool and the dataset is still there. What's more, when I tried to unlock the volume, I got the following error: https://imgur.com/A9gQE81.

I tried again and it worked without error. Though it seemed like it took longer that usual, but that might be because I was watching it. The zpool status seemed normal too (https://imgur.com/fytXMoE) with all the drives online. I even watched a couple movies from the Movies share with no problem.

I'm going to replace another drive tonight or tomorrow night just to see if the dataset size will shrink again. Will post the results.

Also, should I report that error when unlocking the pool to the bug tracker?

 

[Jurgen Segaert]

This is normal/expected in a Z1 configuration, as you have one drive for parity; as per the manual: http://doc.freenas.org/11/storage.html#view-volumes

Code:

The first represents the ZFS pool and its Used and Available entries reflect the total size of the pool, including disk parity. The second represents the implicit or root dataset and its Used and Available entries indicate the amount of disk space available for storage.

 

[DrKK]

This is normal/expected in a Z1 configuration, as you have one drive for parity; as per the manual: http://doc.freenas.org/11/storage.html#view-volumes

Code:

The first represents the ZFS pool and its Used and Available entries reflect the total size of the pool, including disk parity. The second represents the implicit or root dataset and its Used and Available entries indicate the amount of disk space available for storage.

Yeah I was just about to say!

It dawned on me suddenly what the confusion was.

Sir, the first line, indicating the pool, shows your *gross* storage. The second line, indicating the dataset, shows your *net* storage. Therefore, in a RAID-Z configuration, you will naturally show "one drive's worth" less of storage.

This is totally normal and it has been this way the whole time, you just didn't notice.

:)

 

[DrKK]

Just to convince you, here's mine. "tank" is a RAID-Z2 with 5x4TB. "ssd" is a single SSD.

 

[danb35]

This is totally normal and it has been this way the whole time, you just didn't notice.

More precisely, it's been this way since the release of 9.3. Before that, only one (the pool itself, or the root dataset; don't remember which) was shown.