On a Linux MD software RAID1 I removed a failed drive and added a new one. (All fine now.) The old drive and the new were never in the system at the same time.
Do I see that right, that adding the old drive to the system (for examination) will not hinder the MD assembly on boot in any way?
I assume that:
- MD will see 3 partitions that belong(ed) to the same RAID,
- but will also know that 2 of those are still part of the RAID and 1 is not
Which superblock data will MD help to sort this right? Is there a “not part of the RAID at the moment” bit? What data makes it clear to the MD subsystem that the old partition is not in fact the sole member of a degraded RAID?
Did the new device/partition get a fresh random member UUID on RAID rebuild?
Adding the old drive and confusing MD could be catastrophic if it chooses the wrong devices for the array. I want to avoid that.