Questions concerning multiple OS and RAID-1

[Felipe Alfaro Solana]

On 22 Mar 2005, at 15:23, Christofer C. Bell wrote:

> On Tue, 22 Mar 2005 00:44:02 +0100, Felipe Alfaro Solana 
> <lkml at mac.com> wrote:
>>
>> Nah! Use hardware RAID-1 (*true* hardware RAID-1, not those crappy
>> pseudo-raid controller some manufacturers sell).
>
> Please keep in mind that, in general, raid1 volumes created with
> hardware raid solutions are *not* portable between machines.  If you
> upgrade your machine, you will more than likely have to reinstall your
> OS cleanly and recreate the mirror using whatever hardware raid tools
> the new motherboard provides.  If your motherboard or hardware raid
> controller experiences a failure, you will either have to replace it
> with identical hardware or you will again need to reinstall your
> operating system clean and recreate the mirror.
>
> Mirroring is extremely low overhead for software raid so if you'd like
> to maintain a portable raid volume, then software raid may be more
> appropriate for your purposes.  I'd further suggest running a 4 disk
> configuration if you want mirrored boot devices for two operating
> systems, 2 disks per OS.

Yes, it's a valid point of view... however, software RAID is equally 
incompatible between different implementations (operating systems, for 
example), so I can only think of hardware RAID as a way of having 
RAID-1 across different operating systems on the same machine.