I've got a couple of boxes (one linux and one Win Vista) that I want to enable the hardware RAID 1 (mirrored drives). I've not worked with RAID before. I don't really know much about RAID, but from what I've gathered from google, it seems like I may have to enable the RAID first in the BIOS and then reinstall. Is that correct or is there a way to enable the onboard RAID without reinstalling? I was hoping to clone the drive with dd and then enable RAID 1 in the bios and viola!

Since one of the machines is my parents' (the Vista box), I'd prefer to do something non-destructive. I may just setup a backup mechanism for them where at least they have the data files backed up to the other drive. If I have to reinstall mine (Debian Lenny), I may bite the bullet and do the reinstall.

For hardware raid, you have to enable this in the bios. I am not certain you have to reinstall, but you do have to reboot, at least.
Software raid 1 can be set up on a running system.

Oh yeah, if it helps, the Debian box is an Abit IL8 motherboard and the Vista box is an HP Pavilion a6642p (Benicia-GL8E motherboard -- which seems to be the OEM version of the ASUS IPIBL-LB).

@centosboy - I didn't see anything in the HP BIOS for this, but I was just reading online that sometimes you have to enter the "raid bios". A link I found said CTRL+i gets you into an intel raid bios.

sorry, this is what i mean, but because diff manufacturers will have diff key sequences to get into their raid settings, i just tried to generalise it by saying 'bios'

If I enable RAID 1 and find that it fails to boot for some reason, can I just switch it back to "off" and have the drive boot back up? Sorry for so many noob questions about RAID. Maybe I just need to find a couple of old drives to experiment with...

just reboot and turn raid off