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

[Robert Millan <rmh@aybabtu.com>]

On Wed, Jul 29, 2009 at 10:43:23AM +0200, Felix Zielcke wrote:
> Am Dienstag, den 28.07.2009, 20:12 +0200 schrieb Robert Millan:
> > On Sun, Jul 26, 2009 at 04:05:31PM +0200, Felix Zielcke wrote:
> > > As requested by Robert on IRC, this is a split from my dmraid patch.
> > > On dmraid devices HDIO_GETGEO returns 0 for all fields, so the current
> > > way of grub_util_biosdisk_get_grub_dev just can't work.
> > > So I use blkid to get the UUID of the device and then a new nested
> > > function to find out the grub device like search does.
> > > 
> > > I think this is with intent from the kernel that it just returns 0's.
> > > Maybe it just can't distinguish between a device mapper setup which goes
> > > over multiple partitions or harddisks of different size not from one
> > > which goes only over complete harddisks with same size like in dmraid
> > > Hm but even if, I think it wouldn't help in case of RAID != 1. Sector
> > > count could be > then last sector of one disk or not?
> > 
> > I keep thinking this is an overkill solution.  We should to discuss more about
> > what's the problem we need to fix, and only ressort to this if we have no
> > other choice.
> > 
> 
> The problem is how do we map a device file to a grub device.
> Especially BSD partitions which only have numbers under Linux?
> I don't know how the devices are called under BSD.

What does grub device mean in this context?  If we're strictly in util/ land,
any arbitrary map will do as long as it's consistent.

If we're in both places, we already avoid making assumptions that there will
be consistency between them, so we don't need to make them now.

-- 
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."