On Mon, Apr 18, 2016 at 02:49:07PM +0200, Pino Toscano wrote: > The drive used for the appliance is a raw (sparse) disk: specify that > explicitly in its -drive qemu command line options, so qemu can skip the > autodetection of its format and save a tiny bit of time. > --- > src/launch-direct.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/src/launch-direct.c b/src/launch-direct.c > index ee0a855..8521e5a 100644 > --- a/src/launch-direct.c > +++ b/src/launch-direct.c > @@ -563,7 +563,7 @@ launch_direct (guestfs_h *g, void *datav, const char *arg) > /* Add the ext2 appliance drive (after all the drives). */ > if (has_appliance_drive) { > ADD_CMDLINE ("-drive"); > - ADD_CMDLINE_PRINTF ("file=%s,snapshot=on,id=appliance,cache=unsafe,if=none", > + ADD_CMDLINE_PRINTF ("file=%s,snapshot=on,id=appliance,cache=unsafe,if=none,format=raw", > appliance); ACK. If I'm right, it seems we don't need any change in src/launch-libvirt.c, because we specify the backing file format ("raw") when creating the overlay in make_qcow2_overlay, and we set the overlay format ("qcow2") when adding the disk XML in construct_libvirt_xml_appliance.