Re: Upgrade, use old one as backup, rinse, repeat.
I do the same on a house scale. Old drives from the house main server RAID set are first re-purposed as MAID for media, then as backups, then as desktops (going all the way back to the days when the server was a K6 with 2 40GB Maxtors).
The current set is due for a change soon. I will probably not put WD though (my luck with them has been terrible).
Biting the hand that feeds IT
