update-grub help

[Tom H]

On Wed, May 26, 2010 at 10:48 PM, Goh Lip <g.lip at gmx.com> wrote:
> On 05/27/2010 03:23 AM, Goh Lip wrote:
>
>> Re; use of "search xxxxx --set xxx " instead of "set root=(hdx,y)
>> and /dev/sdxy" : trying to get you some definitive  information on this,
>> but so far, most of this is "inferred"  through the grub developers
>> mailing list and of course my own experience in failure to boot due to
>> 'movement' in hdx,y and /dev/sdc or /dev/sdd, particularly in grub
>> legacy. Will post to you if I get more information. But I am reluctant
>> to send info that is not indisputatble.
>
> Tom, refer https://help.ubuntu.com/community/UsingUUID
>
> First line writes:
>
> Linux now prefers to use UUID (Universally Unique Identifier), LABEL, or
> symlinks to identify media storage devices on a system. Directly using
> /dev/hd*# or /dev/sd*# is no longer preferred since these device
> assignments can change between system boots:

I am not advocating the use of /dev/sdXY, far from it.

The files in /dev/disk/by-id and /dev/disk/by-uuid are unique symlinks
to /dev/sdXY and are created by udev.

Instead of using "root=UUID=<uuid>", you can use
"root=/dev/disk/by-uuid/<uuid>" to refer in as uniquely a way to the
same partition.

It looks like OpenSuse uses "root=/dev/disk/by-id/<id>" (maybe there
isn't a "root=ID=<id>" option) and it is just as valid and unique a
way as a uuid.