Lindsay Haisley wrote:
> I recently tried a badly needed kernel upgrade on my desktop system,
> moving from kernel 2.6.23-gentoo-r3 to kernel 2.6.29-gentoo-r5.  This
> also required an upgrade of udev from 141 to 151-r4.  When I rebooted
> the box there was no /dev/hda4 which is normally the root filesystem,
> and instead what was the root filesystem had a device name of, I
> believe, "rootfs" in the kernel mount table which had the same files.  A
> number of other mounts were gone as well (there was no /dev/hda at all,
> which has several partitions).
>
> The boot-up stumbled to a halt at a maintenance mode prompt with the
> root filesystem mounted R/O and of course no gnome desktop.  I could use
> mount -o remount,rw / to make the root filesystem RW, which allowed me
> to re-emerge an earlier version of udev and boot to the previous kernel,
> but I'm stuck with an aging kernel, and other tools depend on a kernel
> and udev upgrade so sooner or later I'm going to be just, plain,
> stuck :(
>
> The drive setup is a bit complex.  The actual hard drive mounting
> (excluding things like proc, udev, devpts, etc.) look like:
>
> /dev/hda4 on / type reiserfs (rw,noatime)
> /dev/mapper/main_vg-fmouse on /home/fmouse type reiserfs (rw,noatime,notail)
> /dev/hda1 on /home/fmouse/win98 type reiserfs (rw,noatime,notail)
> /dev/mapper/main_vg-win_xp on /home/fmouse/winxp type reiserfs (rw,noatime,notail)
> /dev/mapper/main_vg-backup on /home/fmouse/winxp2 type ext3 (rw,noatime)
> /dev/mapper/main_vg-archive on /home/fmouse/archive type reiserfs (rw,noatime,notail)
> /dev/hda2 on /boot type ext3 (rw,noatime)
>
> The /dev/mapper/main_vg-* block devices are LVM logical volumes
> consisting of Linux RAID-1 arrays which contain an archive and a couple
> of filesystems for a VMware installation.  The underlying drives are
> SATA drives which show up as /dev/sd[a-d]1 in /dev.
>
> This setup must be maintained in a functional state across any kernel
> and udev upgrades.
>
> I've been careful to use the .config from the working kernel as the
> start for configuring a kernel for the newer kernel, using make
> oldconfig.
>
> Does anyone have any idea what's wrong here?  Am I required in recent
> kernels to identify all physical drives in /etc/fstab (and anywhere else
> it matters) with a UUID instead of a /dev device name?  I've wasted an
> entire day on this problem, which I can ill afford, but I have to get
> past this roadblock and get my kernel up-to-date.
>
>    


I ran into this a few weeks ago.  I to have the old IDE hard drives.  I 
had to switch to PATA which means my drives are now sd* instead of hd*.  
I don't use LVM tho.  I set LABELS on mine and use that to boot and 
mount the partitions where that are supposed to mount.  It worked pretty 
well and since I'm using LABELS I can also boot the older kernels and 
hopefully any future kernels that come out.

I *think* LVM can use LABELS to.  If so, that would be my suggestion.  
That way you can move things around as needed and them still boot as 
they still be able to find your partitions.

So far, I have not been able to get Grub to see the LABELS.  I just 
haven't been able to do much testing on it yet.

I'm not sure this will help you but it may be something that you want to 
check into.  If LVM can work with this, it should be backward compatible 
with the kernels.

Hope that gives you a idea at least.

Dale

:-)  :-)