Unable to mount the root fs on stable/8 r264339, GENERIC kernel, with MBR, FreeBSD slice, and UFS volume labels

Sat Apr 12 12:06:51 UTC 2014

On Fri, 11 Apr 2014 21:05-0700, Chris H wrote:

> > On Fri, 11 Apr 2014 10:04-0700, Chris H wrote:
> >
> >> > Hi,
> >> >
> >> > I have a couple of uncritical systems running stable/8 r258344.
> >> > Hardware is Dell OptiPlex GX260, BIOS A09, which is the latest rev.
> >> >
> >> > The r264339 GENERIC kernel are unable to mount the root fs from the
> >> > hard drive using MBR, FreeBSD slice, and UFS volume labels.
> >>
> >> You didn't indicate where it won't mount the drives from. Is this from
> >> the releng_8 install media. In other words, When booting the install
> >> media, the installer can't find the drive(s)? Or is it something else?
> >> When you're presented with the problem, what's the output of ls /dev
> >> do any of ad0* da0* show up? If so, what's the output from
> >> gpart list ad0s1 and the likes?
> >
> > It's when the kernel attempts to mount the root fs from the hard
> > drive during startup.
> >
> > Booting the old kernel, r258344 from November 19th, 2013, works as
> > expected.
> >
> > Typing ? at the mountroot> prompt presented by the new and faulty
> > kernel reveals acd0 and ad0 as GEOM managed disk devices. The kernel
> > printed a few lines or so above the mountroot> prompt that it
> > perfectly detected the ad0 harddrive.
> >
> > The latest kernel simply can't find /dev/ufs/root nor /dev/ad0s1a.
> >
> > Here's the output from various commands:
> >
> > trond at amanda:~>uname -a
> > FreeBSD amanda.[withheld] 8.4-STABLE FreeBSD 8.4-STABLE #0 r258344: Tue Nov 19 21:33:39 CET
> > 2013     root at amanda.[withheld]:/usr/obj/usr/src/sys/AMANDA  i386
> >
> > trond at amanda:~>gpart show ad0
> > =>       63  976773105  ad0  MBR  (465G)
> >          63  976773105    1  freebsd  [active]  (465G)
> >
> > trond at amanda:~>bsdlabel ad0s1
> > # /dev/ad0s1:
> > 8 partitions:
> > #          size     offset    fstype   [fsize bsize bps/cpg]
> >   a:    2097152          0    4.2BSD        0     0     0
> >   b:    4194304    2097152      swap
> >   c:  976773105          0    unused        0     0     # "raw" part, don't edit
> >   d:    2097152    6291456    4.2BSD        0     0     0
> >   e:    8388608    8388608    4.2BSD        0     0     0
> >   f:    4194304   16777216    4.2BSD        0     0     0
> >   g:   41943040   20971520    4.2BSD        0     0     0
> >   h:  913858545   62914560    4.2BSD        0     0     0
> >
> > trond at amanda:~>df -ah
> > Filesystem            Size    Used   Avail Capacity  Mounted on
> > /dev/ufs/root         989M    215M    694M    24%    /
> > devfs                 1.0k    1.0k      0B   100%    /dev
> > /dev/ufs/home         3.9G    694M    2.9G    19%    /home
> > /dev/ufs/tmp          989M    7.1M    903M     1%    /tmp
> > /dev/ufs/usr           19G    8.2G    9.7G    46%    /usr
> > /dev/ufs/var            2G    326M    1.5G    18%    /var
> > /dev/ufs/amandahd0    422G    6.0k    422G     0%    /var/spool/amanda/hd0
> > procfs                4.0k    4.0k      0B   100%    /proc
> > linprocfs             4.0k    4.0k      0B   100%    /usr/compat/linux/proc
> > linsysfs              4.0k    4.0k      0B   100%    /usr/compat/linux/sys
> >
> > The results are the same on the spare system.
> >
> > There I first wiped the harddrive clean, by booting from the
> > 8.0-RELEASE dvd1, ran dd if=/dev/zero of=/dev/ad0 bs=128M, before I
> > installed 8.0-RELEASE. I then transferred an up-to-date working copy
> > of stable/8 to the spare system. Next, I compiled world and the
> > GENERIC kernel, without any hassle. I performed make installkernel and
> > rebooted.
> >
> > The boot loader managed its way through the maze, read /etc/fstab and
> > found the entry for the root filesystem. The new GENERIC kernel,
> > however, simply can't understand what to do with:
> >
> > vfs.root.mountfrom="ufs:/dev/ufs/root"
> > vfs.root.mountfrom.options="rw"
> >
> > as presented by the boot loader. Mind you, the boot loader hasn't been
> > replaced yet. Maybe that's the whole issue, however weird it sounds.
> > /boot/loader.conf is empty btw.
> >
> > I'm doing a similar attempt in VirtualBox at home as I write this.
> > There I began with 8.4-RELEASE, and are currently compiling stable/8
> > r264351.
> >
> > I'll later try in VBox, 8.4-R -> stable/8 with GPT + UFS, using GPT
> > labels, just to rule out UFS labels.
> 
> Looks to me like you're suffering a mix of MBR + GPT. It /appears/ to
> be expecting one of them, but getting the other.

Wrong. I haven't mixed MBR and GPT. And if I did, and if I did use GPT 
labels, then the labels wind up in /dev/gpt, not /dev/ufs.

> Did you install the bootcode, or update it? Was it consistent with 
> your choice of schemes (GPT v MBR)? Well.

The bootcode is usually installed only when creating the filesystems. 
The boot loader gets updated as part of make installworld. I never 
perform make installworld ahead of make installkernel.

> Looks like you're on the right track. As far as I can see. Good 
> luck. :)

I'm trying at least. ;-)

> >> > r258344 obviously can.
> >> >
> >> > I even tried regular device names like /dev/ad0s1a in /etc/fstab, and
> >> > at the mountroot> prompt, i.e. ufs:/dev/ad0s1a. The kernel still
> >> > cannot mount the root fs.
> >> >
> >> > The new kernel (r264339) does recognize the ad0 harddrive, and ad0 is
> >> > listed as one of the GEOM managed disk devices; acd0 being the other
> >> > one.
> >> >
> >> > Do I need to load additional geom modules, or is it a genuine bug?
> >> >
> >> > I have recreated the same conditions on a spare GX260, yes, I have
> >> > plenty of them.
> >> >
> >> > In addition there was some problems with the USB subsystem, so I
> >> > disabled USB in the BIOS for now. USB is not essential for any of my
> >> > systems.
> >> >
> >> > Maybe it's time to leave stable/8 and enter stable/10 or stable/9.
> >> > I'll try to compile stable/9 on the spare system, and see how it
> >> > fares.
> >> >
> >> > Any thoughts regarding the problem mounting the root fs?

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