disk devices in F9 interchanged

[Matt Domsch]

On Wed, Mar 26, 2008 at 03:08:41PM -0400, Will Woods wrote:
> 
> On Wed, 2008-03-26 at 11:57 -0400, Clyde E. Kunkel wrote:
> > Joachim Backes wrote:
> > > I my actual F8, I have 2 disk devices: One Sata-Disk: /dev/sda, and 1 
> > > IDE-Disk: /dev/sdb.
> > > But in F9 Beta, these two disks seem to be interchanged (/dev/sda <--> 
> > > /dev/sdb). Is this true, and if yes, why?
> > > 
> > > Regards
> > > 
> > Should drive detection change from alpha to beta? Does it really make 
> > any differnce?
> 
> Yes, drive detection may change between alpha and beta. It could change
> depending on the phase of the moon. 
> 
> Device names are dynamically assigned and may change without warning or
> reason. DO NOT RELY ON THEM STAYING THE SAME BECAUSE THEY WON'T.

Amen.
 
> This is why we use filesystem labels, UUIDs, etc.

and mac addresses for NICs.

While there may be a passing resembelance of Linux device names to
what you think a device should be named based on how you plugged in
various cables, don't expect those to stay the same or be consistent.
Doing so, you _will_ get bit some day.  Use characteristics intrinsic
to the device itself (labels, mac addrs, ...) rather than some
perceived topology, and you'll be much happier in the long run.

-- 
Matt Domsch
Linux Technology Strategist, Dell Office of the CTO
linux.dell.com & www.dell.com/linux