Kernel Configuration Question

[Mike Reinehr]

On Friday 22 December 2006 10:50, Mike Reinehr wrote:
> Would someone please help me with what, I think, should be a fairly simple
> kernel configuration question. I am attempting compile a new AMD64 kernel
> that will boot without using an initrd.img file. I've done this a number of
> times before, but this time I can't seem to get it working. Every time, I
> end up with a kernel panic, unable to mount root device.
>
> First, I have a pair of SATA drives set up in a RAID 1 configuration, two
> primary partitions (EXT3) and GRUB installed in the boot sector. The first
> partition is mounted as /boot. The second partition is set up as a physical
> volume group within which are defined the
> usual /root, /home, /var, /usr, /tmp & swap as logical volumes. All this
> was set up with the latest Debian-Installer beta (Etch RC1) and boots
> perfectly with a stock kernel (linux-image-2.6.18-3-amd64).
>
> I've tried to locate all of the modules necessary to boot and compile them
> into the kernel, but I must be missing something.
>
> When I attempt to boot with my kernel,
> 	1)	GRUB locates and boots the kernel from /boot;
> 	2)	The SATA drives are recognized;
> 	3)	md & device-mapper modules are initialized;
> 	4)	The RAID arrays are recognized;
> 		md: Autodetecting RAID arrays
> 		md: autorun ...
> 		md: ... autorun DONE.
> but then:
>
> VFS: Cannot open root device "mapper/vg0-root_lv" 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)
>
> I considered adding a "root=" boot option, as the message said,
> but /dev/mapper/vg0_root_lv is the correct logical volume.
>
> TIA
>
> cmr

I hate to answer my own posting but it belatedly has occurred to me that 
perhaps it's not possible to mount a root partition using LVM without an 
initrd.img. I've booted without an initrd.img before & I've used LVM before, 
but not with the root partition as part of the logical volumes. Yes, no, 
maybe?
-- 
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"More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC