Debian: installed from USB, now Grub has incorrect devices

lefty.crupps · 10-18-2010, 02:43 PM

Created a USB installer of the Debian 5.0.x netinstall disk using UNetBootin on XP.

The Debian 5.0 install went fine, but at bootup Grub failed to find my devices. I had to manually edit the Grub boot line to change the hd1,0 and /dev/sdb1 to hd0,0 and /dev/sda1:

Code:

title           Debian GNU/Linux, kernel 2.6.26-2-amd64
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.26-2-amd64 root=/dev/sda1 ro 
initrd          /boot/initrd.img-2.6.26-2-amd64

After the recent 64bit kernel vulnerability we upgraded the kernel, and this issue happened again, where the hd1,0 and sdb1 are set in the Grub menu.lst file, when they should be hd0,0 and sda1 (as they are above)

What is causing the system to set the devices incorrectly? Where can I change this so that future upgrades etc don't mess up the boot process?

pljvaldez · 10-18-2010, 03:10 PM

One thing you can do is change the grub menu.lst file to use the UUID or label of the device. See this part way down for use of UUID.

lefty.crupps · 01-11-2011, 01:03 PM

> One thing you can do is change the grub menu.lst file to use the UUID

With Grub2 won't this just get overwritten with future updates?

j1alu · 01-11-2011, 04:28 PM

With grub2 yes, but with Debian5 you have got grub-legacy, not grub2.
(grub2 uses /boot/grub/grub.cfg, btw).

Have a look at /boot/grub/device.map