help: why can't my hand-rolled kernel mount an LVM root FS?

[manoj.iyer at canonical.com]

You could diff the config files to see what you are missing.

Also, look here for help on building Ubuntu kernels:
https://wiki.ubuntu.com/Kernel/Dev
http://kernel.ubuntu.com/~kernel-ppa/mainline/daily/


Cheers
--- manjo

On Tue, 6 Jul 2010, Robert P. J. Day wrote:

>
>  disclaimer:  i *really* hate asking what are simple questions on
> this list but i've run out of ideas.
>
>  for a while, i was configuring, building, installing and booting new
> kernels with the following recipe:
>  ... configure, build ...
>  $ sudo make modules_install
>  $ sudo make install
>  $ sudo update-initramfs -c -k 2.6.35-xxxx (whatever)
>  $ sudo update-grub
>
> worked great on my previous laptop, where i'd installed ubuntu 10.04
> with one monstrous, ext4 filesystem.  all my new, hand-built kernels
> worked great.
>
>  recently upgraded to a new laptop and decided to get clever and
> created a small ext4 filesystem for /boot, and the rest of root in
> /dev/mapper/lynx-root.
>
>  my ubuntu-packaged kernels have no problem booting, but my new
> hand-rolled kernel (2.6.35-rc4) chokes and dies thusly when booted in
> recovery mode:
>
> md: ... autorun DONE
> VFS: Cannot open root device "mapper/lynx-root" on unknown-block(0,0)
>
>  so ... i conclude that somehow i've omitted providing proper LVM2
> support somewhere.  in the kernel?  in the initrd?  what awesomely
> trivial step have i forgotten?  lvm2 is certainly installed on this
> machine and, as i said, the ubuntu packaged kernels have no problem.
>
>  help?
>
> rday
>
> -- 
>
> ========================================================================
> Robert P. J. Day                               Waterloo, Ontario, CANADA
>
>        Top-notch, inexpensive online Linux/OSS/kernel courses
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>
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