The first method that comes to mind is to make a raw copy of each mirrored disk to another disk attached to the same server. dd if=/dev/sda of=/dev/sdb will do a raw dump from one drive to another. Assuming you copy to a drive of equal or greater capacity, your partition structure, RAID superblock (including UUID), and data should remain intact. mdadm should be able to run a disk pair made by raw copies of the disks. I don't see a problem with identical UUID drives living in the same machine, so long as the array isn't started. Obviously copying a mounted block device is a bad idea, so I'd do it from a bootable CD environment, etc. - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html