On 4/28/11, Gleb Natapov gleb@redhat.com wrote:

of virt stack. You should use libvirt or virt-manager instead. Especially if you are concerned about security. I think libvirt can start guest on headless server.

If this still fails for you you need to complain to libvirt developers (not in a rant mode, but providing details of what exact version of software you have problem with and what are you trying to do). And libvirt developers will not be shy to complain to qemu developers if the problem turned to be on their side.

I've finally got an installation working, not using virt-install or virt-manager. After reading through the libvirt site, I started writing the domain definition manually.

Through trial and error, comparison with what virt-install generated and the online examples, I got a working xml. Just for the record, virsh --version reports 0.8.1

For the benefits of other newbies, my discovery so far is that

1. No-activity after the guest VM started Originally, when I specified the CentOS DVD ISO, the guest will load and then do nothing but chew up 100% CPU cycle on the allocated 1 vcpu for quite some time. Subsequently, it appeared that mounting the ISO as loop back is the solution. This seemed to imply that libvirt or KVM couldn't boot a guest from ISO... which didn't quite make sense.

I ran into the issue when using my manually generated XML, it turned out that the reason was the permissions (644) on vmlinuz and initrd.img on the DVD. By copying the two files to local disk, changing the permissions and using the <initrd> and <kernel> options, I was able to boot the guest.

I was curious how virt-install got around this and learnt that I could dump the config from a running machine. It turns out that virt-install didn't exactly use the .xml it created, it added stuff to the running version. Importantly making a temporary copy of initrd.img and vmlinuz. I think the ISO problem with virt-install may be that it was unable to mount the ISO to copy these files despite me running it as root.

2. Anaconda couldn't see the DVD Which was my rant earlier, since it sounded really stupid that the installer couldn't see the disc it just booted off. Now, with #1 solved, it seems that anaconda wasn't booting off the disc after all.

However, the interesting thing here is that once I got past #1, My guest could install from the DVD.

After comparing the xml files, it seems the problem is virt-install did not save the path to the ISO/mounted DVD. Under the <disk> element, there wasn't a source. With my manually generated xml, specifying the ISO as the source worked.

But the virt-installed anaconda was complaining I don't have any hard disks or cdroms. Not that there was no disk in the drive. Everytime I picked an option like install media in HDD or CDROM, it prompted me no device, do I want to install a driver. Since the hard disk definition appears to be the same, I'm not sure why that happened with virt-install's xml but not mine.

So right now, I managed to get the OS installed, rebooting it required removing the initrd and kernel entry as well as the source so that it would boot from the image disk.

Only problem is... networking still isn't working although brctl show on the host shows that a vnet0 had been created and attached to the bridge. Any pointers would be appreciated!