I have two SATA drives set up in a RAID 1 mirror using Intel's ICH8R/9R/10R raid controller. I actually have three drives, but I want to rotate them around from time to time and keep one shelved to act as a backup. My question is, if I want to do a rotation does the drive I'm swapping in have to be formatted and empty? If it instead contains an older backup of my current system data will that cause problems or can I make the raid controller overwrite its contents with the other half of the mirror during the rebuilding process?
STOP! A backup to do what? That's WHY you have a RAID1...If one drive fails, you can still boot and rebuild the array, rotating drives just puts the SAME data back on the replaced drive... READ ABOUT RAID, don't just make uninformed decisions...
I hope I'm not the only one who is going to say this, but RAID is not a backup. RAID1 is not a backup.
RAID1 is giving me redundancy in case of a single drive failure. But there are many other ways to lose data across the entire array, and having an actual BACKUP stored away separately mitigates that risk. I'm not exactly storing government secrets, but some of it is 10-ish years old and has a lot of sentimental value. It's really such a small task to back things up every few months so I'd rather take the extra precautions.
At least, I *imagine* it's a small task. Not having to format the third drive each time would make things much simpler, but no one's answered my question yet.
I agree, I'm thinking to do the same. My RAID1 is to make sure that I can ALWAYS use the data on the drives (redundancy). However, once a month I now create a backup on an external drive and take it offsite.
It's just the idea of not backing up (which takes about 24 hours) but just swapping one of the drives. Theoretically it would be healthier for the drive to be offline every now and then, plus I don't need to worry about backup, since the NAS will rebuild the drive for me.