building LVM kernels for RH

[James McDonald]

On Tue, Jun 28, 2005 at 05:08:28PM -0500, Net Llama! wrote:
> Anyone here had any success building your own 2.6.x kernel from the
> pristine kernel.org source on a RH system that is using LVM (either RHEL4
> or FC3/4)?
> 
> I've tried using an initrd and also compiling in support for LVM into the
> 2.6.12.1 kernel, and both times, the root filesystem can't be found on
> bootup:
> VFS: Cannot open root device "mapper/VolGroup00-LogVol00" or
> unknown-block(0,0)
> Please append a correct "root=" boot option
> Kernel panic - not syncing: VFS: Unable to mount root fs on
> unknown-block(0,0)
> 
> Surely there has to be a way to do this without using RH's kernel?
> 

I think the LVM uses something called a device mapper to create "/dev/mapper/VolGroup00-LogVo100"

Which I *think* is related to BLK_DEV_DM which needs to be enabled. I don't know what the config you are building from is like so this is a bit of a guess.

I have found in the past that I had to set a physical path to the root=LABEL=/ option redhat uses. Perhaps try root="/dev/mapper/VolGroup00-LogVo100". But that was without an initrd.

Initrd should still be the same.