After some pondering, think I've figure it out. Best way to go is to set it up with --create --level=1 --raid-devices=2 for the initial pair of drives, then --fail --remove the rotate-out drive, then --add the alternate drive. Now there will be three drive slots with one "removed" and two "active". To rotate a drive off-site --fail --remove go to the off-site, swap the drives and on return --re-add the rotate-in drive. This way the 'mdadm' UUID labels will stay on the drives and 'mdadm' will warn against mistakes such as trying to use the wrong drive for a mirror pair. Will always have one "removed" drive. The --grow --raid-devices=1 --force and --grow --raid-devices=2 --add would be used only if a drive fails and needs to be replaced. If anyone disagrees please advise. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
