From: "H. Peter Anvin" <hpa@zytor.com>
To: Matt Domsch <Matt_Domsch@dell.com>
Cc: Gene Heskett <gene.heskett@gmail.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Querying the bios from booted linux kernel?
Date: Sat, 05 Jan 2008 11:47:20 -0800 [thread overview]
Message-ID: <477FDEC8.3020605@zytor.com> (raw)
In-Reply-To: <20080105041828.GB6011@auslistsprd01.us.dell.com>
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
prev parent reply other threads:[~2008-01-05 19:47 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-05 0:13 Querying the bios from booted linux kernel? Gene Heskett
2008-01-05 0:47 ` H. Peter Anvin
2008-01-05 2:14 ` Alan Cox
2008-01-05 2:45 ` H. Peter Anvin
2008-01-05 4:18 ` Matt Domsch
2008-01-05 19:47 ` H. Peter Anvin [this message]
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