I understand that RAID should not be used for backups but what about using it to create backups on physical level? I have a setup of regular rsync backups from all the network to one server. Once a week, all the backups are copied to an external HDD (straightforward with dd) and the HDD is carefully carried home, to prevent loss of data in case something happens with the server room.
Now, would it be a good idea to have a RAID1 array of two or more disks and instead of copying the data - just switch the disk with another one and rebuild the array? Will it be a problem to restore the data from the extracted disk afterwards?