Back to the original question. Is the spare showing as faulted in my initial post because it is currently resilvering? Once it's done resilvering can I just run an extended SMART on the drive that FreeNAS dropped from the mirror? If it passes an extended SMART how would I go about getting it re-entered into the pool and my spare back to being a spare? I believe the drive is not actually failing but rather the HBA due to over-heating incurred write errors causing FreeNAS to think the drive was failing and dropping it out of the pool. It is currently logging an occasional write error on the spare during the resilver and I am worried it is going to drop the spare before the resilver finishes. I find it highly unlikely that all of my drives started failing simultaneously after 6 months of use when they started experiencing ATA error counts but no SMART failures.