Given a hot-swappable 15 spindle RAID 10 array with two failed disks. There is one global hot spare, and it is actively "sparing" the first of the two failed disks. The array is running, but has no further redundancy mechanisms.
Onsite tech reports the "spared" disk has a green LED, despite being marked failed in array management software. The "unspared" disk is amber.
In what sequence would you replace the failed disks? Spared first? Unspared first? Both at once?
Unspared for sure. That mirror is at risk, where the mirror that is rebuilt with the hot spare is redundant.
The answer is none. There's no such thing as a 15 spindle RAID10 array. RAID10 requires an even number of disks (spindles).