Re: grub 1.99 configuration

[Bruce Dubbs]

Vladimir 'φ-coder/phcoder' Serbinenko wrote:
> On 12.06.2011 04:28, Bruce Dubbs wrote:
> > I'm trying to manually run grub-mkconfig to establish grub-1.99
> > installation instructions for Linux From Scratch.
> >
> > I am getting:
> >
> > grub-mkconfig -o /boot/grub/grub.cfg
> >   /usr/sbin/grub-probe: error: cannot stat `/dev/root'
> >
> > Doing some investigating grub-mkconfig is running:
> >   /usr/sbin/grub-probe --target=device /
> >
> > Drilling down, grub-probe is doing:
> >   device_name = grub_guess_root_device (path);
> >
> > Which in turn is doing:
> >   grub_find_root_device_from_mountinfo( "/", NULL );
> >
> > This is reading /proc/self/mountinfo.  The problem here is that this
> > file does not give the device, but specifies /dev/root:
> >
> > 13 1 8:15 / / rw,relatime - ext3 /dev/root
> > rw,errors=continue,barrier=0,data=writeback
> >
> > The kernel is 2.6.39.1, but 2.6.37 seems to give the same thing.
> > grub-probe should be able to detect /dev/sda15, but fails on newer
> > kernels.
> >
> > grub-probe for grub-1.98 works fine.  A grep there shows no use of
> > /proc/self/mountinfo.
> >
> > Suggestions?
> update either udev or grub. normally /dev/root should be a symlink.
> Newer grub-probe can cope with some other arrangements as well

Well I'm using udev-171.  That is the most recent version.  We don't 
like to non-release package versions in LFS, but we do occasionally 
patch files.

I don't know when /dev/root became a 'device'.  Udev doesn't create it. 
 We also don't use an initrd.  That's not needed when you know in 
advance what your hardware configuration is.

I did work around the problem by manually creating the symlink.  I do 
not know of anything other than GRUB that needs it, but I don't use lvm.

In any case, I don't think GRUB should choke because /dev/root is missing.

  -- Bruce