Disk devices changed after upgrade to current

[Barney Cordoba]

--- On Sat, 7/11/09, Kamigishi Rei <spambox at haruhiism.net> wrote:

> From: Kamigishi Rei <spambox at haruhiism.net>
> Subject: Re: Disk devices changed after upgrade to current
> To: "Matt Smith" <freebsd at xtaz.co.uk>
> Cc: freebsd-current at freebsd.org
> Date: Saturday, July 11, 2009, 10:23 AM
> Matt Smith wrote:
> > I have just upgraded my system from 7.2 to 8.0 using a
> source based
> > upgrade. After rebooting it for the first time the
> server unfortunately
> > failed to come back up. I had a look at the console
> and found that it was
> > failing to find the root device and prompting me for
> it. By manually
> > entering it I managed to boot the server and could
> then see the problem.
> > 
> > In the 7.2 fstab my root partition and swap space were
> ad4s1a and ad4s1b
> > but after booting the 8.0 kernel these seem to have
> changed to ad4a and
> > ad4b so I set the new names in the fstab and it's now
> working fine. I read
> > through the UPDATING file before I did this but I
> couldn't see any warnings
> > that this may occur. The only entry that's possibly
> relevant is 20090320
> > talking about GEOM_PART.
> >   
> If you check June'09 archives, you'll find out that there
> already was a question about this, coming from a person with
> FreeBSD installed on a dangerously dedicated disk.
> Are you sure you aren't using a DDD (a drive that has no
> DOS/GPT partition tables, just the bsdlabel)?
> 
> --
> Kamigishi Rei

This, unfortunately, is a common problem. There are devices detected in 8 that are not detected in 7 (or vice versa). You can try disabling acpi but that causes different problems. I wasn't able to get 7 and 8 synced in terms of detecting disks no matter what settings I used.

Barney