Kernel Configuration Question

[Net Llama!]

On Fri, 22 Dec 2006, Mike Reinehr wrote:
> 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?

I dont' know, but if need to have support for LVM, the filesystem (ext3), 
& your sata controler compiled into the kernel to have any chance of this 
working.

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Lonni J Friedman                        netllama at linux-sxs.org
LlamaLand				http://netllama.linux-sxs.org