Re: [RFC][PATCH] unique sigs in the msdos label

[Andrew Clausen]

On Fri, Jun 25, 2004 at 05:38:11PM -0500, Matt Domsch wrote:
> For comment and review, not necessarily inclusion yet.
> 
> I've got Linux kernel code which tries to determine what the BIOS boot
> disks are by storing the "mbr_signature" field (offset 440 in the MBR,
> which is at the end of the boot_code section) for each of the
> int13_dev8x devices, and presenting this to userspace through
> /sys/firmware/edd/int13_dev8x/mbr_signature.  Then userspace can read
> the MBR itself from /dev/{sda,hda,...}, compare the signatures, and
> match disks.  This works if system-unique values are stored in each
> disk's mbr_signature field in the MBR, and doesn't rely on BIOS EDD
> 3.0 to be available, or if available, correctly implemented. :-)

What about partition tables that were created by Microsoft?

This is only going to be a problem with >1 disk anyway, right?
If there is >1 partition table, aren't the partition tables going
to be different, anyway?  Use memcmp?  I guess this could be useful
for RAID mirrored disks?

Cheers,
Andrew