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Date: Wed, 8 Feb 2012 16:44:00 +0000 (GMT)
From: Paul Parsons <lost.distance@yahoo.com>
Subject: Re: No /dev/root with devtmpfs?
To: Kay Sievers <kay.sievers@vrfy.org>, Kirill Smelkov <kirr@mns.spb.ru>
Cc: linux-kernel@vger.kernel.org
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--- On Wed, 8/2/12, Kirill Smelkov <kirr@mns.spb.ru> wrote:
> "On what disk/partition was / mounted?" is a well-defined
> question for
> cases when backing store is local hdd, so there should be
> well-defined
> answer.
> 
> Previously it was /dev/root, but if /dev/root is not good
> there should be
> some other way for getting the answer. With ext2 I've
> switched to
> `mountpoint -d /` and then grepping major/minor in
> /proc/partitions, but
> with major=0 case I suspect this won't work.
> 
> 
> My use case is to check md5 sum of mbr + bootloader area +
> root-partition early right after the boot, to verify whether
> software is
> not corrupt, and for doing so it was useful to know / ->
> root-partition
> -> whole block device. It's not tivo, just checking for
> medium damage. (I
> understand this would be better done in the early bootloader
> but that
> part is out of my control)

Could you simply use /etc/fstab to identify the root partition?