[clug] grub boot problems
Rodney Peters
rodneyp at pcug.org.au
Mon Aug 4 12:38:50 GMT 2008
Some BIOS appear to re-number drives starting from the boot drive. It may well be that the automatically generated menu.lst is correct and boot commands should be relative to (hd0). Amending the device.map file appears to have no effect in this circumstance.
Many distro don't have an option to set other than sda as the GRUB boot device. In order to work around that you need to boot, via HDD to achieve appropriate device mapping, to the GRUB> prompt. Note that booting from CD or floppy at this stage may give different drive mapping and erroneous results.
Then tab complete your way through the boot process, to boot from any distro on a HDD. Next run GRUB from a booted distribution and again use tab completion of the "device (hd" command to figure out how GRUB numbers the drives. Then re-run the GRUB setup on whichever drive maps to sdc.
It does not matter whether sdc is recognised as (hd0), (hd1) or (hd2) as long as it has control of the boot process.
You may then need to amend menu.lst to make root, kernel & initrd commands relative to whatever (hdn) actually contains the desired files.
Rod
On Monday 04 August 2008 18:58:24 linux-request at lists.samba.org wrote:
> From: Paul <mylists at wilsononline.id.au>
> To: CLUG List <linux at lists.samba.org>
>
> I have been using Linux for some years but my experience seems to fail me
> here
>
> I'm migrating my O/S + data to a new SATA drive and I have set my BIOS Boot
> priority for my new drive as top.
>
> I assumed I set my grub root command to boot off this drive as per
> device.map which is here: (note I want to boot (hd2)
> (hd0) /dev/sda
> (hd1) /dev/sdb
> (hd2) /dev/sdc
> ~
>
> Initially I tried
> root (hd2,1)
> but I got Error 22: partition not valid
>
> Arrggg.
>
>
> here is Partition table for /dev/sdc (root is part#2) I hope
>
> GNU Parted 1.8.6
> Using /dev/sdc
> Welcome to GNU Parted! Type 'help' to view a list of commands.
> (parted) p
> Model: ATA SAMSUNG HD501LJ (scsi)
> Disk /dev/sdc: 500GB
> Sector size (logical/physical): 512B/512B
> Partition Table: msdos
>
> Number Start End Size Type File system Flags
> 1 32.3kB 107MB 107MB primary ext3 boot
> 2 107MB 21.6GB 21.5GB primary ext3
> 3 21.6GB 23.7GB 2147MB primary linux-swap
> 4 23.7GB 500GB 476GB primary ext3
>
>
> menu.lst
> splashimage=(hd0,1)/boot/grub/splash.xpm.gz
> hiddenmenu
> title Fedora (2.6.25.11-60.fc8) new
> root (hd0,1)
> kernel /boot/vmlinuz-2.6.25.11-60.fc8 ro root=LABEL=/ rhgb quiet
> initrd /boot/initrd-2.6.25.11-60.fc8.img
More information about the linux
mailing list