update-grub help

[Goh Lip]

On Wed, 26 May 2010 14:24:09 -0400
Tom H <tomh0665 at gmail.com> wrote:

> On Wed, May 26, 2010 at 11:14 AM, Goh Lip <g.lip at gmx.com> wrote:
> > On 05/26/2010 10:10 PM, Dave Howorth wrote:
> >


> Goh: I have never used Suse/OpenSuse, but it looks like they use the
> by-id symlinks and the entries in Ubuntu's grub.cfg must have been
> picked up from OpenSuse's menu.lst (or grub.conf if it uses RHEL
> terminology).
> 
> Dave: I assume that OpenSuse uses grub1 so you might need to change
> "set root=(hd5,1)" to "set root=(hd5,2)" to adjust for the change in
> partition numbering between grub1 and grub2. The output of
> bootinfoscript would be helpful in this respect.
> 
> You can also boot into Ubuntu to do what Gog is suggesting above by
> edit /etc/grub.d/40_custom to add your OpenSuse install (and using
> copy-and-paste for the uuids!).
> 
> $ cat 40_...
> #!/bin/sh
> cat <<EOF
> menuentry "OpenSuse custom" {
> set root=(hd5,1) or set root=(hd5,2)
> linux /boot/vmlinuz-2.6.31.5-0.1-desktop root=UUID=xxxxxxxxxxx ro
> initrd /boot/initrd-2.6.31.5-0.1-desktop
> }
> 
> Or using OpenSuse's disk id way
> (you might be able to use "root=ID=ata..." but
> "root=/dev/disk/by-id/ata..." should work)
> 
> $ cat 40_...
> #!/bin/sh
> cat <<EOF
> menuentry "OpenSuse custom" {
> set root=(hd5,1) or set root=(hd5,2)
> root=/dev/disk/by-id/ata-WDC_WD5001AALS-00L3B2_WD-WCASYA878047-part1
> ro initrd /boot/initrd-2.6.31.5-0.1-desktop
> }


Tom, it's really very late for me here and just to shoot off a few quick
points. 

Thanks for the notes on suse syslinks

Re (hd5,1) (hd5,2), my message to Dave on checking via 
grub> search -f /boot/vmlinuz-2.6.31.5-0.1-desktop [gives you hd5,1 ?]
would confirm this.

I think I made a mistake in my last message on chainload to Dave, there
should be a drivemap -s (hd0) (hd5) somewhere but I don't know exactly
what. (don't use mapping chainload), If Dave needs help on this, I will
not be able to help him. Can you please correct my mistake? I'll still
suggest linux /boot/vmlinuzxxxxxx .....

Re; use of "search xxxxx --set xxx " instead of "set root=(hdx,y)
and /dev/sdxy" : trying to get you some definitive  information on this,
but so far, most of this is "inferred"  through the grub developers
mailing list and of course my own experience in failure to boot due to
'movement' in hdx,y and /dev/sdc or /dev/sdd, particularly in grub
legacy. Will post to you if I get more information. But I am reluctant
to send info that is not indisputatble.

Good to hear from you. Take care.

Regards - Goh Lip