[Fedora-xen] NFS Booting - Kernel modification

[Paul Wouters]

On Mon, 26 Feb 2007, Abhishek Gaurav wrote:

> I have been trying to boot a VM over NFS with the default xen-kernel that came
> with FC6. However, I ran into the problems like:

> VFS: Cannot open root device "nfs" or unknown-block(0,255)
> Please append a correct "root=" boot option
> Kernel panic - not syncing: VFS: Unable to mount root fs on
> unknown-block(0,255)

You are missing drivers from the initrd. I am not sure if you can grab the
ramdisk (initrd) over the network, obviously you need some network drivers first.

> After some search, it looks like that the CONFIG_IP_PNP and CONFIG_ROOT_NFS
> parameters need to be enabled in the kernel. Can anyone please let me know how
> to go about it in the default fc6-xen system. It also looks like that I do not
> have the source for the xen-enabled kernel.

install the kernel-xen-devel package. Then either change the config-*
files or, which is easier, you can run rpmbuild -bp which sets up the
build/linux-* directory and patch everything, and then you can run make
config and make bzImage yourself.

Paul