What are the general replacement requirements for a failed RAID 1 (mirrored) or 5 (parity) hard drive?
Does the replacement drive have to be exactly the same (1) model and/or (2) size of the original failed drive? With regard to replacement size, I assume it would have to be at least the same size or larger.
Can I use a solid-state drive in place of a traditional magnetic drive? Or vice-versa?
Best Answer
In theory, you can mix-and-match the disk types as much as you want as long as the replacement disks are all of the same greater size.
In practice, you really do NOT want to mix the drive types: it introduce a level of complexity (because the disk physical layout are different) that usually causes the whole thing to be much slower afterward. Depending on the exact controller type, it might also simply not work.
Also, the performance of the whole array will be linked to the performance of the slowest disk: using an SSD in there will not help at all.
The only occasions when I could imagine this to be of any advantage would be:
It's a really good time to check your backups, though: a single failed read on any of the disks in the array during rebuild and your data is toast. That's why I wouldn't recommend rebuilding the arrays any more frequently than you absolutely have to.