[Libguestfs] Fedora 18 / Rawhide switch over to using libvirt as the back end

[Richard W.M. Jones]

On Sun, Aug 19, 2012 at 10:05:28PM +0100, Richard W.M. Jones wrote:
> Just a note [possibly more of a warning] that I'm intending to switch
> the default backend in Fedora 18+ to libvirt this week.  For more
> information about what this means, see:
> 
>   https://rwmj.wordpress.com/2012/07/23/new-in-libguestfs-use-libvirt-to-launch-the-appliance/#content
> 
> Barring any bugs, the change ought to be transparent.  The reasons why
> we're making this change in Fedora are:
> 
>  - Because in RHEL 7 this will be the default and we want to test it.
> 
>  - Improved encapsulation and security through sVirt.
> 
>  - Allows us to implement advanced features, especially disk
>    hotplugging and access to remote disks.
> 
> Note there's no change upstream.  libvirt still isn't required.

It took a while, but this should happen today.

  In Rawhide: libguestfs >= 1.19.36-1.fc19
      In F18: libguestfs >= 1.19.36-1.fc18

To tell if your version of libguestfs uses libvirt do:

  $ guestfish get-attach-method
  libvirt

(If it prints 'appliance' instead of 'libvirt', then it's using the
non-libvirt direct launch method).

There ought to be no user-visible change.  If you want you can switch
back to using the direct launch method by doing:

  export LIBGUESTFS_ATTACH_METHOD=appliance

If you want to change the libvirt URI used, do something like:

  export LIBGUESTFS_ATTACH_METHOD=libvirt:qemu:///system

(It sounds tempting, but this won't let you use Xen etc, although it
is now plausible that someone could patch libguestfs to make that work.)

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://et.redhat.com/~rjones/virt-df/