ZFS RAID1+0 one mirror 512B, the other 4k

[garfunkel]

I have a bit of an issue.

I have a RAID 1+0 setup in my NAS with 2x2TB HDDs. I am upgrading one disk from each mirror to 4TB, so that I should end up with each mirror having 2+4TB of storage.

Now, I managed to replace one of the disks using the GUI perfectly fine. When I tried to replace the second drive, in the other mirror, the GUI responded with an error stating that the drive can't be replaced because the mirror vdev would have incompatible sectors. I checked with zdb and for some reason one of the mirrors is 4k and the other is still 512B. I looked around and found two sysctl commands which allowed me to replace one of the 2TB drives in the problem mirror with the new 4TB drive.

The problem now is that I still will have one mirror with 4k sectors, and the other without. Is there any way at all that I can replace/resilver both drives in the dodgy mirror to be 4k without having to recreate the entire pool? I really don't want to destroy the pool and loose my data. :(

 

[garfunkel]

Ah dammit I'm an idiot, I realised just now that I am to replace both drives from the mirror, not one from each. grrr!

Now I have to wait for the current resilver to finish before I can do that.

Still, even when I do finish, I will still have the 2x4tb mirror with 4k sectors, and the other 2x2tb mirror with 512b sectors. Is there anyway to fix that second mirror?

 

[budmannxx]

Still, even when I do finish, I will still have the 2x4tb mirror with 4k sectors, and the other 2x2tb mirror with 512b sectors. Is there anyway to fix that second mirror?

Not without destroying and recreating the mirror.

Also, you didn't specify what HDDs you have, but if they're not 4K disks, then you can't do it at all. (Hopefully that was obvious.)

 

[paleoN]

Also, you didn't specify what HDDs you have, but if they're not 4K disks, then you can't do it at all. (Hopefully that was obvious.)

Unless you manually create a new pool from the CLI.

 

[garfunkel]

The 2TB drives are WD Caviar Greens. One of the mirrors using them already had 4k sectors and I don't ever remember setting that, it must have done that by default. No idea why the other mirror wasn't 4k though (same HDDs)...

The 4TB drives are WD Caviar Reds.

To re-create the mirror, I would need to re-create the pool right because ZFS doesn't allow destruction of vdevs in a stripe?

BUGGER. I love ZFS but it has some strange limitations for us home users. :(

 

[budmannxx]

Unless you manually create a new pool from the CLI.

You're right, of course. I assumed (but shouldn't have) that the CLI was beyond the scope, given the initial question.

The 2TB drives are WD Caviar Greens. One of the mirrors using them already had 4k sectors and I don't ever remember setting that, it must have done that by default. No idea why the other mirror wasn't 4k though (same HDDs)...

The 4TB drives are WD Caviar Reds.

To re-create the mirror, I would need to re-create the pool right because ZFS doesn't allow destruction of vdevs in a stripe?

BUGGER. I love ZFS but it has some strange limitations for us home users. :(

I'm not too familiar with ZFS mirrors so hopefully someone with more expertise can chime in here. But I think you may be able to take one of the mirrors offline, destroy it, recreate with 4k sectors, and re-mirror from the "original" 4k mirror. Obviously backup your data before attempting this.