Having a working RAID and data mirroring set up on your server/PC is great for when your one of your hard disks dies, but what to do when this really happens to you? How do you get that data back?
I like RAID. On my development server, I use both hardware and software RAID. For hardware RAID on FreeBSD, I like 3Ware. For software RAID, I tend to use gmirror, because I don’t need more than RAID-1.
Some time ago I added two 120GB HDD to this system. One was SATA, one was PATA. They were joined together via gmirror. Tonight I received some errors that one of the drives was failing. I replaced the drive, and recovered the mirror. I’ll show you what I did, mostly so I know what to do the next time it happens, but also so you can see what to do as well.