Need to Pull Disk in Mirrored VDEV for RMA. DETACH or OFFLINE?

OpenZFS TrueNAS
1

Hello,

I’ve got a healthy (for the moment) mirror vdev in a pool that’s still thrown enough serious SMART errors in a short amount of time that inquired with the seller, and they requested that I RMA it. I don’t have a spare right now, so I can’t replace it until I get the RMA replacement disk back in the mail.

I’d like to (1) remove it from the present mirror, (2) without converting the mirror to a stripe, and (3) be able to pop the new disk in when it comes and have the mirror re-silver itself and go.

Fortunately, the mirror (and the pool) are empty of data, so I’m not worried about losing data this point but do want to make sure I understand how I’m supposed to do this.

In STORAGE > Pool > Pool Devices, I can see the impacted mirror, and the disk. sdh in my case.

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My understanding is that if I Detach the disk, I’d convert the mirror to a stripe.
However, if I Offline the disk, the mirror is preserved but I can safely remove the troubled disk and send it off.

Then, once I get the new disk, I detach the offline disk, and feed it the new one (after burn-in, of course).

Is that the correct process?

Thanks!

2

It doesn’t much matter either way; a single-disk vdev can be converted into a mirror vdev any time you like. Technically, a single-disk vdev is a mirror vdev already–it’s just a single device wide, whereas the more traditional “mirror” vdev is two devices wide.

With that said, if you want to dot your eyes and cross your tees as perfectly as possible, OFFLINE is what you want here.

3 Likes
3

Thanks!

(As annoying as this is to have to do so quickly, at least I’m getting to learn new ZFS things. :stuck_out_tongue: )