X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=tools%2Fvirt-resize;h=8a473ca3fcf39047e1d67b94f60ae134d8935042;hp=6e11d475ac7c4000eb29525d28e035e7e22e20d2;hb=bf0280bf589573c11529999a73e9ec642dea9d61;hpb=0dc1f8e7aeb390e72125f459930850b8050318df

diff --git a/tools/virt-resize b/tools/virt-resize
index 6e11d47..8a473ca 100755
--- a/tools/virt-resize
+++ b/tools/virt-resize
@@ -78,6 +78,11 @@ remaining space to /dev/sda2:
 
  virt-resize --resize /dev/sda1=+200M --expand /dev/sda2 olddisk newdisk
 
+As above, but the output format will be uncompressed qcow2:
+
+ qemu-img create -f qcow2 newdisk.qcow2 15G
+ virt-resize --expand /dev/sda2 olddisk newdisk.qcow2
+
 =head1 DETAILED USAGE
 
 =head2 EXPANDING A VIRTUAL MACHINE DISK
@@ -230,6 +235,25 @@ contents of a partition.  Deleting a partition removes it completely,
 but note that it also renumbers any partitions after the one which is
 deleted, which can leave some guests unbootable.
 
+=head2 QCOW2 AND NON-SPARSE RAW FORMATS
+
+If the input disk is in qcow2 format, then you may prefer that the
+output is in qcow2 format as well.  Alternately, virt-resize can
+convert the format on the fly.  The output format is simply determined
+by the format of the empty output container that you provide.  Thus to
+create qcow2 output, use:
+
+ qemu-img create [-c] -f qcow2 outdisk [size]
+
+instead of the truncate command (use C<-c> for a compressed disk).
+
+Similarly, to get non-sparse raw output use:
+
+ fallocate -l size outdisk
+
+(on older systems that don't have the L<fallocate(1)> command use
+C<dd if=/dev/zero of=outdisk bs=1M count=..>)
+
 =head1 OPTIONS
 
 =over 4
@@ -492,6 +516,36 @@ my $quiet;
 
 Don't print the summary.
 
+=cut
+
+my $format;
+
+=item B<--format> raw
+
+Specify the format of the input disk image.  If this flag is not
+given then it is auto-detected from the image itself.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+Note that this option I<does not> affect the output format.
+See L</QCOW2 AND NON-SPARSE RAW FORMATS>.
+
+=cut
+
+my $output_format;
+
+=item B<--output-format> raw
+
+Specify the format of the output disk image.  If this flag is not
+given then it is auto-detected from the image itself.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+Note that you still need to create the output disk with the right
+format.  See L</QCOW2 AND NON-SPARSE RAW FORMATS>.
+
 =back
 
 =cut
@@ -511,6 +565,8 @@ GetOptions ("help|?" => \$help,
             "d|debug" => \$debug,
             "n|dryrun|dry-run" => \$dryrun,
             "q|quiet" => \$quiet,
+            "format=s" => \$format,
+            "output-format=s" => \$output_format,
     ) or pod2usage (2);
 pod2usage (1) if $help;
 if ($version) {
@@ -538,8 +594,13 @@ sub launch_guestfs
 {
     $g = Sys::Guestfs->new ();
     $g->set_trace (1) if $debug;
-    $g->add_drive_ro ($infile);
-    $g->add_drive ($outfile);
+    my @args = ($infile);
+    push @args, readonly => 1;
+    push @args, format => $format if defined $format;
+    $g->add_drive_opts (@args);
+    @args = ($outfile);
+    push @args, format => $output_format if defined $output_format;
+    $g->add_drive_opts (@args);
     $g->set_progress_callback (\&progress_callback) unless $quiet;
     $g->launch ();
 }
@@ -1180,7 +1241,9 @@ sub restart_appliance
 
     $g = Sys::Guestfs->new ();
     $g->set_trace (1) if $debug;
-    $g->add_drive ($outfile);
+    my @args = ($outfile);
+    push @args, format => $output_format if defined $output_format;
+    $g->add_drive_opts (@args);
     $g->launch ();
 
     # Target partitions have changed from /dev/sdb to /dev/sda,
@@ -1380,6 +1443,23 @@ Windows may initiate a lengthy "chkdsk" on first boot after a resize,
 if NTFS partitions have been expanded.  This is just a safety check
 and (unless it find errors) is nothing to worry about.
 
+=head2 GUEST BOOT STUCK AT "GRUB"
+
+If a Linux guest does not boot after resizing, and the boot is stuck
+after printing C<GRUB> on the console, try reinstalling grub.  This
+sometimes happens on older (RHEL 5-era) guests, for reasons we don't
+fully understand, although we think is to do with partition alignment.
+
+ guestfish -i -a newdisk
+ ><fs> cat /boot/grub/device.map
+ # check the contents of this file are sensible or
+ # edit the file if necessary
+ ><fs> grub-install / /dev/vda
+ ><fs> exit
+
+For more flexible guest reconfiguration, including if you need to
+specify other parameters to grub-install, use L<virt-rescue(1)>.
+
 =head1 ALTERNATIVE TOOLS
 
 There are several proprietary tools for resizing partitions.  We
@@ -1396,6 +1476,13 @@ hand-calculating sector offsets, which is something that virt-resize
 was designed to avoid.  If you want to see the guestfish-equivalent
 commands that virt-resize runs, use the C<--debug> flag.
 
+=head1 SHELL QUOTING
+
+Libvirt guest names can contain arbitrary characters, some of which
+have meaning to the shell such as C<#> and space.  You may need to
+quote or escape these characters on the command line.  See the shell
+manual page L<sh(1)> for details.
+
 =head1 SEE ALSO
 
 L<virt-list-partitions(1)>,
@@ -1410,6 +1497,11 @@ L<resize2fs(8)>,
 L<ntfsresize(8)>,
 L<virsh(1)>,
 L<parted(8)>,
+L<truncate(1)>,
+L<fallocate(1)>,
+L<grub(8)>,
+L<grub-install(8)>,
+L<virt-rescue(1)>,
 L<Sys::Guestfs(3)>,
 L<http://libguestfs.org/>.