Re: [PATCH] use UUID to map system devices to grub devices

[Robert Millan]

On Wed, Aug 05, 2009 at 08:18:29AM +0200, Felix Zielcke wrote:
> Am Dienstag, den 04.08.2009, 23:19 +0200 schrieb Robert Millan:
> > On Fri, Jul 31, 2009 at 06:26:51PM +0200, Felix Zielcke wrote:
> > > 
> > > If we'd do an arbitrary mapping then `grub-probe -t drive' would show
> > > the wrong grub device.
> > > But except from this I think that would be okay.
> > 
> > We can never garantee that `grub-probe -t drive' will show the "right" 
> > drive,
> > at least on i386-pc, because we don't know how is BIOS going to order them.
> 
> Yes drive not, but the partition.

It's true, but we don't really make the distinction.  UUID search will find
a filesystem, which is in a partition (usually), and doesn't rely on partitions
being reliable.

That's fortunate!  It means we don't have to commit to partition numbers being
reliable, even if they are right now.

Because of this (unless I missed something), at the end of the day the
unreliability issue you described doesn't translate into any real problem
for us.  It just adds more to a problem we already solved.

> Unfortunately we don't have UUID support on every filesystem we support
> like JFS. But I think it's not that commonly used.

Adding UUID support to new filesystems is very easy.  I did the first ones
with just 5-10 minutes of research and a few lines of coding.

Would you like to do JFS ?

-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."