[libvirt-users] Problems using virt-install to create KVM CentOS 5.6 guest

I was having problems creating a KVM CentOS 5.6 Initially the host was CentOS 5.6 but I switched to Scientific Linux 6 during the process of trying to solve it. I was able to install a working guest in the end by manually writing an XML and using virsh. However, as it shouldn't be so complicated, Gleb over at the KVM list asked me to share this with the libvirtd ML. I don't know it's an old bug, since current libvirt seems to be several sub-versions ahead of mine so decided to post to the user list first in case it's a known bug. Hopefully somebody will be able to pinpoint what went wrong. Host system: SL 6.0 with libvirtd (libvirt) 0.8.1 Network: 2 physical NICs, eth0 bridged to br0 for WAN connectivity, eth1 is for internal use Installation medium: CentOS 5.6 DVD ISO Original problem virt-install would simply not work, I get a blank console with nothing happening and qemu-kvm will be 100% load on one core. This was eventually traced to virt-install not being able to mount/use the ISO. Mounting the ISO as loopback allowed the installation to proceed. However, the guest was not able to see the installation "cdrom". With httpd running off the host, and tested accessibly via Internet, a network install did not work either. After much frustration, I followed the documentation at libvirt website to write my own XML file. The result of this was the discovery that 1. permissions on initrd.img and vmlinux was not allowing virsh access - copying these files to disk and adjusting the xml allowed installation to proceed. virt-install appears to do this on the fly. 2. virt-install guest could not see any disk. The anaconda installer could not find any CDROM or hard disk. - Part of the problem seems to be that virt-install did not save the source for the installation medium, the generated XML did not have the source information under the <disk> element. I specified this in my manual XML and the CentOS guest was able to see the "cdrom" and install properly. As I did not have any problem with missing hard disks with my manually written XML so I'm not sure what went wrong with virt-install's 3. Can't install via network - This was traced to networking not working at all. Even in my manual XML, networking did not work although the guest could install from the disk. Eventually, this was solved by adding the <model type='virtio' /> to the device definition.