On 8/14/06 3:12 PM, "Istvan Gabor" <suseuser04@freemail.hu> wrote:

Hello all:

I've got a technical question:

Currently I have an 160 GB Samsung SATA HD in my system. I would like to put in another 160 GB Maxtor HD and have my whole system (all my current HD) mirrored. As I know this would be a RAID mirror. My questions: 1. Is it possible to set up a mirrored system if I have data already on one of the drives? 2. If yes what would be the process?

I have an ASUS KN8 mobo that can do SATA RAID according to the manual.

I'm not positive about that particular motherboard, but most of the ASUS boards use the Silicon Image 3114 chipset. It's hardware RAID functionality does not work under linux 2.6.x kernels (and trying to install SuSE 10.1 onto a disk connected to it, with hardware RAID enabled, will almost always fail in my experience). So, assuming that board does use the SiI 3114 chipset, you don't want to go that way. Even if it uses a different chipset, it's probably going to wipe the data -- the hardware device will generally need to write some meta data to the front of the disk, to begin with, and will simply overwrite the front end of your partition (and the filesystem metadata) in order to do so. Software raid is tricky, because "Linux RAID" is a distinct partition type (I want to say it's type "FD" as opposed to the type "83" of linux data partitions, and "82" of linux swap, but I don't have a quick way to check that right at the moment). I'm not sure, but maybe you can create an md device on the new disk, as a degraded (single-disk) RAID-1; create a filesystem on it; copy the data to it; fix up the bootloader; and then add in the old disk as the second drive in the RAID-1 array...seems risky, if it's even possible... If you're using less than 50% of the physical disk at the moment, you could shrink your current filesystems/partitions down so that > 51% of the disk is free; create a Linux RAID partition on the now-free space; create a Linux RAID partition of the same size on the new disk, and then create the RAID-1; cp -ax or rsync your current install to the RAID 1; fix up your bootloader; reboot, get rid of your old install, and then expand the Linux RAID partitions out so they fill the disk. On the other hand, if you've got an external drive of some description, you could just use rsync or cp -ax to move your entire install there; create the RAID; cp or rsync the stuff back onto the internal disks; and use the repair tool (or command line) to fix the MBR... Worth noting that the last of these is the only one that I would really consider "safe", if you don't have a very good backup process in place. The first two don't require an external drive, so the investment is smaller, but you very definitely do run the risk of losing/corrupting data as you push partitions around on the disk.