On Wed, Oct 05, 2016 at 03:00:40PM +0100, Andrei Perietanu wrote:

Hi Andrea,
  Thanks for the reply;
  To shed some more light on the matter I performed a few more tests; each
time doing a clean install. I installed ubuntu14.04 as the guest OS,
keeping everything else the same.
On my custom Linux I've created ubuntu VMs before (using ide drivers) and
it all works file. This time I created the VM using virtio disk drivers and

So switching only the guest OS (keeping the host OS, domain XML and
everything) works, so how can the problem be anywhere else than the
guest OS?  You might be, most probably, missing some kernel option.
What is the difference between the installer and the system installed?
Are they using the same kernel?  Accessing the same things?

the installation didn't even finish. It reported a disk related error
saying it's not being able to read from /dev/vda. I restarted the
machine...same error.

You're adding more configurations into the mix, let's skip that and only
talk about what you had before, the IDE and ubuntu/your distro.

   Just to make sure that I have not messed anything up, I did the same on
the ubuntu host, so installed ubuntu guest on an ubuntu host uding the same
guest config xml. This time everything worked fine. So it looks like a
problem with the kvm virtio drivers.

   I was trying to stay away from updating the qemu package because adding
the package takes a long time (usually, because of missing dependencies),
but I'm not sure I have any other option at this point...

Are there that many since 1.1.2?  I don't think that much has changed.
But it should be solvable without updating (plus the update might not
fix it for you.