One of my drives started throwing udma CRC errors. It passed the extended SMART test and disk check without error. I wanted to rule out sata cable/port, so I shut down, switched to a different cable/port, and fired it back up. The array started up emulating the missing drive from parity, with the disk in question showing as unassigned. I stopped the array and tried putting the disk in its place, but it listed as a "new device" and starting the array would have rebuilt the drive from parity. I shut down, swapped back to the original cable/port, and started it up again. Once again, the drive was emulated and the disk was unassigned.

 

The drive serial matches the "missing" drive (since it's the same one). Is there anything I can do to restore the array without a rebuild? My plan is to move everything off this drive and remove it from the array. Thank you

 

EDIT: Googled some more and it appears that once a disk is in this state, there's nothing I can do to simply re-add it to the array as is and it will need to be rebuilt. Confirmation would be appreciated, though I'll hold out hope for something better.

Edited March 7, 20215 yr by Crlaozwyn

44 minutes ago, Crlaozwyn said:

EDIT: Googled some more and it appears that once a disk is in this state, there's nothing I can do to simply re-add it to the array as is and it will need to be rebuilt. Confirmation would be appreciated, though I'll hold out hope for something better.

That's the general way to do it.

 

Alternatively instead of rebuilding the drive you would do a Tools - New Config, keep all the assignments and when starting the array make sure you check off that Parity is already valid.

 

BUT, the downside to that is that a write to the drive did indeed fail (hence why the drive is disabled), and since the write failed, Parity reflects the write, but the drive doesn't.  Ergo, the contents of the drive differs (slightly) from what is currently being emulated.

Thank you for explaining not only the "what" but the "why" behind it. I replaced the SATA cable and am choosing to rebuild the drive; since I'm not sure whether the write error is impactful, I'm going to err on the side of caution. I wasn't aware of the alternate option of using a new config for this; I've only used that when dropping a drive. Great tip though - thanks again.