A pretty generic approach:
Your error is: mount: could not find filesystem '/dev/root'
There can be 2 reasons: either the disk device drivers are not found, which is plausible in virtualization land, or the filesystem device driver is not found;
I bet the 1st one is the case, although I've erred years in the past forgetting to build in support for ext2 (at that time)
Your steps would be:
1st: identify the filesystem type (ext4, reiserfs, ...) and disk type (ide, virtio, scsi, ...)
2nd: check if support is available in the kernel for either, and you have it compiled in (if not, enable it and recompile your kernel)
In the case of a virtio disk type, you may have to make an initrd with at least the modules virtio, virtio_blk and virtio_pci. (maybe more, doing this from the top of my head)
You may have to run some setup commands for your bootloader to recognize your initrd (if you have one) and kernel.
Last edited by Ramurd; 09-25-2010 at 04:29 AM.