RAID : Can i add a mirror drive?

[lance_biscuit]

Ive currently got 2 250gb hitachi sata 2 drives in raid performance mode my question is can i add another drive that will just mirror the raid possibly to a seperate controller, ie an ide controller. My other drive that I have that Im thinking of using for it is a 200gb ibm/hitachi

 

[Messiah Khan]

Technically yes. But the mirror drive would need to be the same size as the drive its mirroring, ie, in your case 250gb. And you'd need two mirror drives to mirror your excisting 2 drive setup. AFAIK, you'd also need to format all the drives to set up the RAID.