Bug#614143: os-prober: generated linux entries don't use UUIDs for root= parameter

[Colin Watson <cjwatson@debian.org>]

On Sat, Feb 19, 2011 at 11:36:00PM +0100, Matthias Berndt wrote:
> As you probably know, os-prober is used by grub-mkconfig to generate grub.cfg
> entries for other operating systems. Today I ran update-grub in order for it to
> pick up the Fedora 14 Kernel I had installed today. The command line it
> generated looked like this:
> linux /boot/vmlinuz-2.6.35.6-45.fc14.x86_64 root=/dev/sdb3
> But with the Fedora kernel the relevant device isn't called /dev/sdb3 but
> /dev/sda3, so this command line doesn't work, and I guess UUIDs should be used
> instead. The following change to /usr/share/os-prober/common.sh did the trick
> for me: replace
> 
> mapdevfs () {
>     readlink -f "$1"
> }
> 
> with
> 
> mapdevfs() {
>     echo "/dev/disk/by-uuid/$(blkid -o value -s UUID "$1")"
> }
> 
> Perhaps this can be applied upstream?

I don't think this is generally safe.  It relies on the kernel in
question coming with an initramfs with suitable UUID support; os-prober
can't reliably know this.

os-prober presumably picked this kernel up from some other boot loader's
configuration file - perhaps /boot/grub/grub.conf in your Fedora system.
Could you please attach that file?

Thanks,

-- 
Colin Watson                                       [cjwatson@debian.org]