update-grub help

[Tom H]

On Tue, Jun 1, 2010 at 9:46 AM, Dave Howorth <dhoworth at mrc-lmb.cam.ac.uk> wrote:
> Tom H wrote:
>> To go back to the OP (who seems to have disappeared)
>
> Hi Tom, thanks for joining in. Hi Goh Lip,
>
> Murphy stepped in right after my last email. My main desktop developed
> an intermittent fault that mad it impossible to use so my focus has been
> on getting that fixed. Then a public holiday intervened ...
>
> Anyway I did meanwhile start the tests Goh Lip suggested ...
>
> Goh Lip wrote:
>> grub> ls (hd5,1)  [write carefully uuid no (do you use label for this?)]
>> grub> search -f /boot/vmlinuz-2.6.31.5-0.1-desktop [gives you hd5,1 ?]
>> grub> search -f /boot/initrd-2.6.31.5-0.1-desktop  [gives you hd5,1 ?]
>>
>> If yes to above, proceed......
>
> And discovered that the problem seems to be somewhere different than
> where we've been looking. It seems that the BIOS, and grub, can't see
> the disk that SUSE is on, while Ubuntu can. So it's probably time to
> describe the machine's hardware a little more.
>
> It has ten disks. The mobo is a Tyan S7010 that has six on-board SATA
> ports (ICH10R) that are connected as follows:
>
> #0 - DVD writer
> #1 - 500 GB Ubuntu system disk
> #2 - 1.5 TB md raid
> #3 - 1.5 TB md raid
> #4 - 1.5 TB md raid
> #5 - 1.5 TB md raid
>
> Then there's a 3ware 9650SE-4LPML with four disks:
> - 1.5 TB 3ware raid
> - 1.5 TB 3ware raid
> - 1.5 TB 3ware raid
> - 1.5 TB 3ware raid
>
> And finally there's a plugin PCI-express 2-port SATA card - Belkin
> F5U251 with just one disk plugged in:
> - 500 GB openSUSE system disk
>
> As far as I can tell, all the hardware is working correctly and
> everything works when Ubuntu is running. Also, I believe the 8 disks
> connected in RAID arrays are not relevant to this issue so I'm basically
> ignoring them. They're presently unused and will just be data stores.
>
> There are some clues in the device.map files. The one produced by running
>
>  sudo grub-mkdevicemap
>
> in Ubuntu looks like this:
>
> (hd0)   /dev/sda
> (hd1)   /dev/sdb
> (hd2)   /dev/sdc
> (hd3)   /dev/sdd
> (hd4)   /dev/sde
> (hd5)   /dev/sdf
> (hd6)   /dev/sdg
>
> which looks like the traditional device.map that is easy to get wrong.
> The one in the openSUSE system (not sure what produced it) looks like this:
>
> (hd1)   /dev/disk/by-id/ata-WDC_WD1503FYYS-01T8B0_WD-WMAUR0310828
> (hd5)   /dev/disk/by-id/ata-ST31500341AS_9VS3BBQ7
> (hd0)   /dev/disk/by-id/ata-Hitachi_HDS721050CLA362_JP1540HN25EWEP
> (hd2)   /dev/disk/by-id/ata-ST31500341AS_9VS39AK8
> (hd4)   /dev/disk/by-id/scsi-3600050e0e812cc005649000090490000
> (hd6)   /dev/disk/by-id/ata-WDC_WD5001AALS-00L3B2_WD-WCASYA878047
> (hd3)   /dev/disk/by-id/ata-WDC_WD1503FYYS-01T8B0_WD-WMAUR0310430
>
> which is potentially a whole lot more useful. They both apparently show
> the same thing, as viewed from a running Linux system. SEVEN devices:
>
> hd0 sda Ubuntu system disk
> hd1 sdb md raid disk
> hd2 sdc md raid disk
> hd3 sdd md raid disk
> hd4 sdg 3ware raid (4 disks)
> hd5 sde md raid disk
> hd6 sdf openSUSE system disk
>
> Unfortunately, using the ls command in grub only shows SIX devices. hd6
> a.k.a sdf a.k.a openSUSE disk, is not there. Checking in the BIOS also
> shows only the same six disks.
>
> Now I don't know whether there's some h/w or BIOS configuration needed
> (I haven't found any options) or some grub config (google hasn't found
> anything) or something completely different?

Try:

Create a device.map in Ubuntu with the same content as the OpenSuse's
or the equivalent /de/disk/by-uuid values and save it (for example) in
/root rather than in /boot/grub.

Run (in Ubuntu)
grub-setup --root-device='(hd0)' --device-map=/root/device.map /dev/sda