root mount error

[Greg Byshenk]

On Tue, Dec 28, 2010 at 01:36:01AM +0100, Damien Fleuriot wrote:
> On 12/27/10 9:18 PM, Michael BlackHeart wrote:

> > I've got trouble with FreeBSD 8 Stable
> > First I've put on notebook 8.2 RELEASE amd64, then SVN'ed src's to
> > yesterday revision I don't remember exact number, but I've have this
> > problem aobut week or two so it's not so important, also as it doesn't
> > work on i386 too.
> > 
> > After installing new kernel I've just build - indeed it always was
> > GENERIC for both arch's on clean system - I've got an a kernel painc
> > caused by disability to mount root partition because kernel couldn't
> > see the drive. By pressing '?' I've sen only acd0 that represents
> > CD-ROM.
> > 
> > In debug messages I haven't found anything about ad0 - than hdd was
> > identified before new kernel was installed.
> > I've got an HP 6720s notebook with SATA 160GB Hitachi HDD that is
> > working with diabled SATA native mode.
> > 
> > I've not found any info 'bout this error in recent 8.Stable so I don't
> > know how to handle this one.

> First, I'd advise making use of FreeBSD's nextboot utility to test new
> kernels:
> http://fuse4bsd.creo.hu/localcgi/man-cgi.cgi?nextboot+8
> 
> Second, I would suggest reading the handbook's excellent section on
> upgrading your machine or rebuilding the kernel:
> http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/updating-upgrading.html
> 
> Now, a likely cause of your problem is the installation of a custom
> kernel with removed support for whatever your hard disk drive or raid
> controller is recognized as.
> 
> Did you reinstall your old, working kernel, or are you actually asking
> for help doing just that ?

What kind of laptop?

For information, I had a similar problem when I updated my laptop
(HP Compaq 6910p) to 8.2-PRERELEASE as of 14 December. For some reason,
the system was no longer seeing the main hard drive. 

I solved the problem by setting 'SATA Native Mode' (or some such) in the
BIOS, which then led my (SATA) drive to be seen at '/dev/ad8'. After 
booting from ad8 and modifying my 'fstab', everything works fine.

So you might try the same thing. At least change the setting in your 
BIOS to see if you can see a drive.

-greg


-- 
greg byshenk  -  gbyshenk at byshenk.net  -  Leiden, NL