Question RE: Replacing a Disk

[NASbox]

I am replacing a disk that is getting old, but has not failed, (it is working/in good health) and the pool is healthy.

Is it necessary to offline the old disk before resilvering is complete?

Am I correct that if the replace operation is performed by selecting "Replace" (without Offline), that during the resilver operation there would be no failed/missing drives?
So if a drive (other than the drive being replaced) failed during the resilver operation, the pool would only experience a single drive failure?

Am I correct, that the drive being replaced can still contribute to pool data security during the resilver/replace operation, or would the pool experience 2 drive failures?

Only once the replace operation is complete, would I offline the old drive.

Can someone please advise. Thanks.

 

[danb35]

Only once the replace operation is complete, would I offline the old drive.

You're correct on everything but this--once the replace operation is complete, the old drive goes offline by itself.

 

[sretalla]

Is it necessary to offline the old disk before resilvering is complete?

No

Am I correct that if the replace operation is performed by selecting "Replace" (without Offline), that during the resilver operation there would be no failed/missing drives?

Yes

So if a drive (other than the drive being replaced) failed during the resilver operation, the pool would only experience a single drive failure?

true

Am I correct, that the drive being replaced can still contribute to pool data security during the resilver/replace operation, or would the pool experience 2 drive failures?

sort-of... together with the existing disk... during resilver it isn't really protecting anything (but the still-online original is).

 

[NASbox]

@danb35, @sretalla thanks very much for the speedy reply - that really helps.

I had a somewhat funky situation that I didn't understand. I replaced anther drive, but forgot to explicitly remove the replaced drive before rebooting. All the drive letter assignments [da0-daX] completely reassigned themselves, and it took a bit of work to find the drive that had been replaced since it had changed it's id. Comments?

 

[sretalla]

Comments?

That's normal. Drive identifiers aren't permanent. ZFS cares about gptids for the partitions in a pool so no need to worry about it changing (but you should look for serial numbers to identify disks properly from the pool to the physical disk.