[Fedora-xen] Re: DomU boot on Fedora 6 fails with 'no root found' error.

[Daniel P. Berrange]

On Wed, Jan 31, 2007 at 08:15:23PM -0800, master at bradleyland.com wrote:
> The problem comes about when you update the kernel with yum. In my
> experience (like all good lessons, learned the hard way), the initrd is
> created on the fly and does not include xenblk. You cannot just take the
> initrd that ends up in the /boot directory and use it for your guest.
> Doesn't work.
> 
> Now I know this, it's an easy matter to create a fresh initrd and include
> the xenblk module. Maybe there's a smarter way to do this. If so, it
> escapes me.

The smarter way is to keep the kernel & initrd / RPM installed inside the
guest OS itself. So doing yum update in the host doesn't have any risk of
breaking your guests, and doing yum update inside the guest will ensure
that the automatically created initrd is correct wrt to that guest's
virtual hardware setup.

The reason the default initrd for kernel-xen in the host is not working
for the guest is that the initrd generated to be suitable for booting the 
host OS which has real hardware.  If you're keeping initrds for the guest
in the host filesystem, then you're always going to have to manually create
yourself a new initrd whenever kernel-xen in the host is upgraded.

Regards,
Dan.
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