Re: [Libguestfs] [PATCH] launch: direct: specify format for appliance drive

Pino Toscano
Mon, 18 Apr 2016 16:51:27 -0000

On Monday 18 April 2016 17:49:22 Richard W.M. Jones
wrote:
> 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.

Yup, that's why only the direct backend was patched.

--
Pino Toscano