Grub stopped working: menu.lst mysteriously altered

[bigred1]

Binary package hint: grub

I had Grub working nicely: Ubuntu Gutsy Gibbon 7.10 on hd0 (a SATA drive), and WinXp on hd1 (an IDE drive).

Then one day the boot was broken, and Ubuntu could not be accssed, although Windows could. Manual edit of the Grub menu from within the Grub shows that hd0 had been altered to hd1. I edited that value in-line, then booted into Ubnutu and edited menu.lst, which had indeed been mysteriously edited. Indeed, the display string for Ubuntu had also been alterd.

I suspect that an auto-update did this. If so, that is very serious, as it rendered Ubuntu unbootable.

 The fixed file is attached -- the broken file simply had hd1 for Linux where it should have had hd0.

(This might be similar to https://bugs.launchpad.net/ubuntu/+source/grub/+bug/5375 )

[bigred1 (brodypierre)]

The fixed menu.lst

[bigred1 (brodypierre)]

The broken autoedited version

[Steve Langasek (vorlon)]

Hi,

the key lines are these:

## default grub root device
## e.g. groot=(hd0,0)
# groot=(hd1,0)

This is in the section of "magic comments" used for autogenerating your boot stanzas with update-grub. You should update this line to point to (hd0,0) as per your current boot stanzas, so that any future updates will use the correct setting.

This has been addressed in the grub package for Ubuntu 8.04 by adding code to update-grub to check for local modifications to the automatically managed kernel list.