Re: Querying the bios from booted linux kernel?

From: H. Peter Anvin
Date: Sat Jan 05 2008 - 14:47:36 EST


Matt Domsch wrote:

parted and fdisk both write into the MBR signature space, so your
disks should have unique MBR values in them.


parted did so incorrectly, and had less than 20 bits of randomness.

fdisk only does so as of a very recent version (I put that in after I noticed a whole bunch of disks I had had zero identifiers.)

sfdisk doesn't at all, last I checked.

None check for collisions.

I've given up trusting any BIOS to get EDD 3.0 device paths right,
there are just too many broken implementations out there, and
seemingly no real desire on the part of the component vendors to fix
it. MBR signatures work pretty well - Dell uses this method for every
one of our factory installed Linux systems we ship, so I _know_ it works.

At least with a known distribution. But yes, it really seems to be the most reliable method.

-hpa


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