I converted a physical maschine running CentOS 4.6 to a Xen VM on a CentOS 5 host. Almost everything was running when I decided to rsync /lib and /usr a while later in order to get updated files and get the one or two non-working programs to work. There are differences because of the xenU kernel I didn't think about. I forgot to exclude rpm database and /lib/modules. Because the synced rpm database doesn't include the xenU kernel anymore I installed the latest one again. I got this warning:
WARNING: No module ata_piix found for kernel 2.6.9-67.0.22.ELxenU, continuing anyway
Looking around I don't have this module for the old kernel (2.6.9-67) either. But it's referenced in modprobe.conf. Nevertheless, I could boot the VM. A locate shows this module in all non-xenU kernels under /lib/modules, sometimes in a scsi, sometimes in an ata subdirectory. I still have a backup of the old setup before the sync and this doesn't contain ata_piix in /lib/modules/2.6.9-67.ELxenU/kernel/drivers/scsi either. And no ata directory.
So, I'm a bit puzzled now. Do I need that module to boot a Xen VM? If not, why is it modprobed? And why do I get this warning from the xenU kernel?
Kai