Young impatient jedi: the disk cache in your image XML configuration file you must remove, or network bandwidth slower than jabba at the NewYork marathon experience you will !

root@jvegln:/etc/libvirt/qemu# cat OpenSolarisGLN-i386.xml

[...]

 <devices>
<emulator>/usr/bin/kvm</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='raw' cache='none'/>