Bug#554790: grub-pc: store grub-pc/install_devices using by-id

[Colin Watson]

On Sat, Jan 30, 2010 at 05:24:06PM +0100, Harald Dunkel wrote:
> Colin Watson wrote:
> > UUIDs are properties of filesystems, not disks or partitions, and the
> > MBR of a hard disk does not have a UUID.
> 
> Since MSDOS partitions are limited to 2TByte partitions anyway, it
> might be wise to look at alternatives, e.g. GPT. GPT _does_ provide
> a UUID in the disk header _and_ in the header of each partition.
> 
> Wikipedia provides an excellent overview:
> 
> 	http://en.wikipedia.org/wiki/GUID_Partition_Table

I am already familiar with GPT, but I do not consider it appropriate to
implement a fix only for one partition table type.  It's not remotely
trivial for users to migrate to GPT, and there are many users affected
by this problem right now on MS-DOS partitions.  We should not tie this
bug in with semi-blue-sky partition table migration plans, especially
since there is no need whatsoever to do so.  by-id is perfectly
sufficient for our needs.

> > For disks, the choices for stable identifiers are based on either
> > the hardware serial number or the bus path taken to reach the disk.
> 
> What about block device emulations, e.g. software RAIDs, LVM, etc?

Let's let Linux worry about how to represent those in by-id, eh?  We
don't need to second-guess it.

Anyway, LVM doesn't matter here because you don't install GRUB to an LVM
(you might have /boot on an LVM, but that's a different matter); RAID
also doesn't matter very much in practice because right now the effect
of installing GRUB to a RAID volume is to install to the boot sectors of
all the constituent disks.  I've tested both scenarios.

-- 
Colin Watson                                       [cjwatson at debian.org]