I would have expected that for a 2-drive system, a RAID rebuild would only be writing to the replacement drive. What data would be written to the old one? Unde

I would have expected that for a 2-drive system, a RAID rebuild would only be writing to the replacement drive. What data would be written to the old one? Under that assumption, my strategy is to isolate these drives in their own 2-drive RAID volume until they fail.