C<value> can be NULL.
+=item $result = $h->debug ($subcmd, \@extraargs);
+
+The C<$h-E<gt>debug> command exposes some internals of
+C<guestfsd> (the guestfs daemon) that runs inside the
+qemu subprocess.
+
+There is no comprehensive help for this command. You have
+to look at the file C<daemon/debug.c> in the libguestfs source
+to find out what you can do.
+
=item $h->download ($remotefilename, $filename);
Download file C<remotefilename> and save it as C<filename>
Get the autosync flag.
+=item $label = $h->get_e2label ($device);
+
+This returns the ext2/3/4 filesystem label of the filesystem on
+C<device>.
+
+=item $uuid = $h->get_e2uuid ($device);
+
+This returns the ext2/3/4 filesystem UUID of the filesystem on
+C<device>.
+
=item $path = $h->get_path ();
Return the current search path.
This is always non-NULL. If it wasn't set already, then this will
return the default path.
+=item $qemu = $h->get_qemu ();
+
+Return the current qemu binary.
+
+This is always non-NULL. If it wasn't set already, then this will
+return the default qemu binary name.
+
=item $state = $h->get_state ();
This returns the current state as an opaque integer. This is
B<This command is dangerous. Without careful use you
can easily destroy all your data>.
+=item $h->lvremove ($device);
+
+Remove an LVM logical volume C<device>, where C<device> is
+the path to the LV, such as C</dev/VG/LV>.
+
+You can also remove all LVs in a volume group by specifying
+the VG name, C</dev/VG>.
+
=item @logvols = $h->lvs ();
List all the logical volumes detected. This is the equivalent
The filesystem options C<sync> and C<noatime> are set with this
call, in order to improve reliability.
+=item $h->mount_options ($options, $device, $mountpoint);
+
+This is the same as the C<$h-E<gt>mount> command, but it
+allows you to set the mount options as for the
+L<mount(8)> I<-o> flag.
+
+=item $h->mount_ro ($device, $mountpoint);
+
+This is the same as the C<$h-E<gt>mount> command, but it
+mounts the filesystem with the read-only (I<-o ro>) flag.
+
+=item $h->mount_vfs ($options, $vfstype, $device, $mountpoint);
+
+This is the same as the C<$h-E<gt>mount> command, but it
+allows you to set both the mount options and the vfstype
+as for the L<mount(8)> I<-o> and I<-t> flags.
+
=item @devices = $h->mounts ();
This returns the list of currently mounted filesystems. It returns
where C<device> should usually be a partition name such
as C</dev/sda1>.
+=item $h->pvremove ($device);
+
+This wipes a physical volume C<device> so that LVM will no longer
+recognise it.
+
+The implementation uses the C<pvremove> command which refuses to
+wipe physical volumes that contain any volume groups, so you have
+to remove those first.
+
=item @physvols = $h->pvs ();
List all the physical volumes detected. This is the equivalent
For more information on states, see L<guestfs(3)>.
+=item $h->set_e2label ($device, $label);
+
+This sets the ext2/3/4 filesystem label of the filesystem on
+C<device> to C<label>. Filesystem labels are limited to
+16 characters.
+
+You can use either C<$h-E<gt>tune2fs_l> or C<$h-E<gt>get_e2label>
+to return the existing label on a filesystem.
+
+=item $h->set_e2uuid ($device, $uuid);
+
+This sets the ext2/3/4 filesystem UUID of the filesystem on
+C<device> to C<uuid>. The format of the UUID and alternatives
+such as C<clear>, C<random> and C<time> are described in the
+L<tune2fs(8)> manpage.
+
+You can use either C<$h-E<gt>tune2fs_l> or C<$h-E<gt>get_e2uuid>
+to return the existing UUID of a filesystem.
+
=item $h->set_path ($path);
Set the path that libguestfs searches for kernel and initrd.img.
Setting C<path> to C<NULL> restores the default path.
+=item $h->set_qemu ($qemu);
+
+Set the qemu binary that we will use.
+
+The default is chosen when the library was compiled by the
+configure script.
+
+You can also override this by setting the C<LIBGUESTFS_QEMU>
+environment variable.
+
+The string C<qemu> is stashed in the libguestfs handle, so the caller
+must make sure it remains valid for the lifetime of the handle.
+
+Setting C<qemu> to C<NULL> restores the default qemu binary.
+
=item $h->set_ready ();
This sets the state to C<READY>. This is only used when implementing
=item %superblock = $h->tune2fs_l ($device);
-This returns the contents of the ext2 or ext3 filesystem superblock
-on C<device>.
+This returns the contents of the ext2, ext3 or ext4 filesystem
+superblock on C<device>.
It is the same as running C<tune2fs -l device>. See L<tune2fs(8)>
manpage for more details. The list of fields returned isn't
This creates an LVM volume group called C<volgroup>
from the non-empty list of physical volumes C<physvols>.
+=item $h->vgremove ($vgname);
+
+Remove an LVM volume group C<vgname>, (for example C<VG>).
+
+This also forcibly removes all logical volumes in the volume
+group (if any).
+
=item @volgroups = $h->vgs ();
List all the volumes groups detected. This is the equivalent