Comment 3 for bug 801098

Hi Louis

Thank you for taking the time to report this bug and helping to make Ubuntu better.

Assuming that you are running on maverick+ the issue with kvm not being able to access the .iso image on your external hard drive is due to the fact that by default the kvm processes that virt-install/libvirt starts run as 'libvirt-qemu'; when your hard drive automounts it does it in user space which means that only your account can do anything on the drive - including reading data which blocks libvirt/kvm access to the iso images.

When you unmount the drive and re-mount it as root it gets a different set of permissions which means that the libvirt-qemu account can access the .iso images.

You could work around this by changing the settings in /etc/libvirt/qemu.conf so that the kvm processes run as root; however you do need to consider the security implications of this (it normally runs as libvirt-qemu for good reasons).

I'm going to mark this ticket as 'Invalid' as I believe this is the expected behaviour for removable drives.