Libguestfs - Dec 2016 - [PATCH v3] v2v: -o vdsm: Add --vdsm-compat flag.

v3:

Change the flag from --vdsm-compat-11 to --vdsm-compat=1.1

Also the --machine-readable output has changed.

I have also added a test.

Rich.

Support for RHEV with RHEL 6 nodes required us to output the old style
qcow2 compat=0.10 images.  Since RHEV 3.6 GA, RHEL 6 has not been
supported as a RHEV node type.  Since RHV 4.1, compat=1.1 is
supported.  (Support for compat=1.1 is uncertain in RHV 4.0 even on
RHEL 7 nodes.)

There are significant downsides to using qcow2 compat=0.10 instead of
the modern default (compat=1.1).

Therefore this patch does two things:

For -o rhev, it drops support for compat=0.10 completely.  You must
use RHV 4.1.

For -o vdsm, it adds an interim flag (--vdsm-compat=0.10 or
--vdsm-compat=1.1) which controls the compat level of the qcow2 output
file.  VDSM should use --vdsm-compat=1.1 when it is known that modern
qemu is available.  We can make this the default later when all RHV
instances have moved to 4.1.

It also adds:

  vdsm-compat-option

to the `virt-v2v --machine-readable' output to indicate that this flag
can be used.

Thanks: Yaniv Kaul, Michal Skrivanek.
---
 v2v/cmdline.ml                 |  7 +++++++
 v2v/output_rhev.ml             |  4 ----
 v2v/output_vdsm.ml             | 11 ++++++++---
 v2v/output_vdsm.mli            |  1 +
 v2v/test-v2v-o-vdsm-options.sh | 11 +++++++++--
 v2v/virt-v2v.pod               | 21 ++++++++++++++++++++-
 6 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/v2v/cmdline.ml b/v2v/cmdline.ml
index 2d0a10a..1d325af 100644
--- a/v2v/cmdline.ml
+++ b/v2v/cmdline.ml
@@ -66,6 +66,9 @@ let parse_cmdline ()    let vdsm_vm_uuid = ref None in
   let vdsm_ovf_output = ref None in (* default "." *)
 
+  let vdsm_compat = ref "0.10" in
+  let set_vdsm_compat s = vdsm_compat := s in
+
   let set_string_option_once optname optref arg      match !optref with
     | Some _ ->
@@ -198,6 +201,7 @@ let parse_cmdline ()      [ L"print-source" ],
Getopt.Set print_source, s_"Print source and stop";
     [ L"qemu-boot" ], Getopt.Set qemu_boot,       s_"Boot in
qemu (-o qemu only)";
     [ L"root" ],    Getopt.String ("ask|... ",
set_root_choice), s_"How to choose root filesystem";
+    [ L"vdsm-compat" ], Getopt.Symbol ("0.10|1.1",
["0.10"; "1.1"], set_vdsm_compat), s_"Write qcow2 with
compat=0.10|1.1";
     [ L"vdsm-image-uuid" ], Getopt.String ("uuid",
add_vdsm_image_uuid), s_"Output image UUID(s)";
     [ L"vdsm-vol-uuid" ], Getopt.String ("uuid",
add_vdsm_vol_uuid), s_"Output vol UUID(s)";
     [ L"vdsm-vm-uuid" ], Getopt.String ("uuid",
set_string_option_once "--vdsm-vm-uuid" vdsm_vm_uuid),
@@ -259,6 +263,7 @@ read the man page virt-v2v(1).
   let print_source = !print_source in
   let qemu_boot = !qemu_boot in
   let root_choice = !root_choice in
+  let vdsm_compat = !vdsm_compat in
   let vdsm_image_uuids = List.rev !vdsm_image_uuids in
   let vdsm_vol_uuids = List.rev !vdsm_vol_uuids in
   let vdsm_vm_uuid = !vdsm_vm_uuid in
@@ -272,6 +277,7 @@ read the man page virt-v2v(1).
     printf "virt-v2v\n";
     printf "libguestfs-rewrite\n";
     printf "colours-option\n";
+    printf "vdsm-compat-option\n";
     List.iter (printf "input:%s\n") (Modules_list.input_modules ());
     List.iter (printf "output:%s\n") (Modules_list.output_modules
());
     List.iter (printf "convert:%s\n") (Modules_list.convert_modules
());
@@ -415,6 +421,7 @@ read the man page virt-v2v(1).
         vol_uuids = vdsm_vol_uuids;
         vm_uuid = vdsm_vm_uuid;
         ovf_output = vdsm_ovf_output;
+        compat = vdsm_compat;
       } in
       Output_vdsm.output_vdsm os vdsm_params output_alloc in
 
diff --git a/v2v/output_rhev.ml b/v2v/output_rhev.ml
index e45043b..3280150 100644
--- a/v2v/output_rhev.ml
+++ b/v2v/output_rhev.ml
@@ -248,10 +248,6 @@ object
     Changeuid.func changeuid_t (
       fun () ->
         let g = open_guestfs ~identifier:"rhev_disk_create" () in
-        (* For qcow2, override v2v-supplied compat option, because RHEL 6
-         * nodes cannot handle qcow2 v3 (RHBZ#1145582).
-         *)
-        let compat = if format <> "qcow2" then compat else Some
"0.10" in
         g#disk_create ?backingfile ?backingformat ?preallocation ?compat
           ?clustersize path format size;
         (* Make it sufficiently writable so that possibly root, or
diff --git a/v2v/output_vdsm.ml b/v2v/output_vdsm.ml
index 7cd94c0..6771daf 100644
--- a/v2v/output_vdsm.ml
+++ b/v2v/output_vdsm.ml
@@ -30,6 +30,7 @@ type vdsm_params = {
   vol_uuids : string list;
   vm_uuid : string;
   ovf_output : string;
+  compat : string;
 }
 
 class output_vdsm os vdsm_params output_alloc @@ -37,13 +38,16 @@ object
   inherit output
 
   method as_options -    sprintf "-o vdsm -os %s%s%s --vdsm-vm-uuid %s
--vdsm-ovf-output %s" os
+    sprintf "-o vdsm -os %s%s%s --vdsm-vm-uuid %s --vdsm-ovf-output
%s%s" os
       (String.concat ""
          (List.map (sprintf " --vdsm-image-uuid %s")
vdsm_params.image_uuids))
       (String.concat ""
          (List.map (sprintf " --vdsm-vol-uuid %s")
vdsm_params.vol_uuids))
       vdsm_params.vm_uuid
       vdsm_params.ovf_output
+      (match vdsm_params.compat with
+       | "0.10" -> "" (* currently this is the default,
so don't print it *)
+       | s -> sprintf " --vdsm-compat=%s" s)
 
   method supported_firmware = [ TargetBIOS ]
 
@@ -149,9 +153,10 @@ object
     ?clustersize path format size      let g = open_guestfs
~identifier:"vdsm_disk_create" () in
     (* For qcow2, override v2v-supplied compat option, because RHEL 6
-     * nodes cannot handle qcow2 v3 (RHBZ#1145582).
+     * nodes cannot handle qcow2 v3 (RHBZ#1145582, RHBZ#1400205).
      *)
-    let compat = if format <> "qcow2" then compat else Some
"0.10" in
+    let compat +      if format <> "qcow2" then compat else
Some vdsm_params.compat in
     g#disk_create ?backingfile ?backingformat ?preallocation ?compat
       ?clustersize path format size
 
diff --git a/v2v/output_vdsm.mli b/v2v/output_vdsm.mli
index 532227a..8e69b6d 100644
--- a/v2v/output_vdsm.mli
+++ b/v2v/output_vdsm.mli
@@ -23,6 +23,7 @@ type vdsm_params = {
   vol_uuids : string list;            (* --vdsm-vol-uuid (multiple) *)
   vm_uuid : string;                   (* --vdsm-vm-uuid *)
   ovf_output : string;                (* --vdsm-ovf-output *)
+  compat : string;                    (* --vdsm-compat=0.10|1.1 *)
 }
 (** Miscellaneous extra command line parameters used by VDSM. *)
 
diff --git a/v2v/test-v2v-o-vdsm-options.sh b/v2v/test-v2v-o-vdsm-options.sh
index 3b7eaae..1de0e17 100755
--- a/v2v/test-v2v-o-vdsm-options.sh
+++ b/v2v/test-v2v-o-vdsm-options.sh
@@ -1,6 +1,6 @@
 #!/bin/bash -
 # libguestfs virt-v2v test script
-# Copyright (C) 2014 Red Hat Inc.
+# Copyright (C) 2014-2016 Red Hat Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -21,6 +21,7 @@
 unset CDPATH
 export LANG=C
 set -e
+set -x
 
 if [ -n "$SKIP_TEST_V2V_O_VDSM_OPTIONS_SH" ]; then
     echo "$0: test skipped because environment variable is set"
@@ -61,10 +62,12 @@ mkdir $d/12345678-1234-1234-1234-123456789abc/master/vms/VM
 $VG virt-v2v --debug-gc \
     -i libvirt -ic "$libvirt_uri" windows \
     -o vdsm -os $d/12345678-1234-1234-1234-123456789abc \
+    -of qcow2 \
     --vdsm-image-uuid IMAGE \
     --vdsm-vol-uuid VOL \
     --vdsm-vm-uuid VM \
-    --vdsm-ovf-output $d/12345678-1234-1234-1234-123456789abc/master/vms/VM
+    --vdsm-ovf-output $d/12345678-1234-1234-1234-123456789abc/master/vms/VM \
+    --vdsm-compat=1.1
 
 # Test the OVF metadata was created.
 test -f $d/12345678-1234-1234-1234-123456789abc/master/vms/VM/VM.ovf
@@ -77,6 +80,10 @@ test -f VOL.meta
 # Test the disk file was created.
 test -f VOL
 
+# Test that a qcow2 file with compat=1.1 was generated.
+test "$(guestfish disk-format VOL)" = "qcow2"
+qemu-img info VOL | grep 'compat: 1.1'
+
 popd
 
 rm -r $d
diff --git a/v2v/virt-v2v.pod b/v2v/virt-v2v.pod
index 4e0c65a..3b65d38 100644
--- a/v2v/virt-v2v.pod
+++ b/v2v/virt-v2v.pod
@@ -199,7 +199,7 @@ QEMU and KVM only.
 
 =item OpenStack Glance
 
-=item Red Hat Enterprise Virtualization (RHEV) 2.2 and up
+=item Red Hat Enterprise Virtualization (RHEV) 4.1 and up
 
 =item Local libvirt
 
@@ -604,6 +604,25 @@ boot an operating system from the first VirtIO disk. 
Specifically,
 F</boot> must be on the first VirtIO disk, and it cannot chainload an
 OS which is not in the first VirtIO disk.
 
+=item B<--vdsm-compat=0.10>
+
+=item B<--vdsm-compat=1.1>
+
+If I<-o vdsm> and the output format is qcow2, then we add the qcow2
+I<compat=0.10> option to the output file for compatibility with RHEL 6
+(see L<https://bugzilla.redhat.com/1145582>).
+
+If I<--vdsm-compat=1.1> is used then modern qcow2 (I<compat=1.1>)
+files are generated instead.
+
+Currently I<--vdsm-compat=0.10> is the default, but this will change
+to I<--vdsm-compat=1.1> in a future version of virt-v2v (when we can
+assume that everyone is using a modern version of qemu).
+
+B<Note this option only affects I<-o vdsm> output>.  All other
output
+modes (including I<-o rhev>) generate modern qcow2 I<compat=1.1>
+files, always.
+
 =item B<--vdsm-image-uuid> UUID
 
 =item B<--vdsm-vol-uuid> UUID
-- 
2.10.2

On Wednesday, 7 December 2016 10:02:49 CET Richard W.M. Jones
wrote:
> Support for RHEV with RHEL 6 nodes required us to output the old style
> qcow2 compat=0.10 images.  Since RHEV 3.6 GA, RHEL 6 has not been
> supported as a RHEV node type.  Since RHV 4.1, compat=1.1 is
> supported.  (Support for compat=1.1 is uncertain in RHV 4.0 even on
> RHEL 7 nodes.)
> 
> There are significant downsides to using qcow2 compat=0.10 instead of
> the modern default (compat=1.1).
> 
> Therefore this patch does two things:
> 
> For -o rhev, it drops support for compat=0.10 completely.  You must
> use RHV 4.1.
> 
> For -o vdsm, it adds an interim flag (--vdsm-compat=0.10 or
> --vdsm-compat=1.1) which controls the compat level of the qcow2 output
> file.  VDSM should use --vdsm-compat=1.1 when it is known that modern
> qemu is available.  We can make this the default later when all RHV
> instances have moved to 4.1.
> 
> It also adds:
> 
>   vdsm-compat-option
> 
> to the `virt-v2v --machine-readable' output to indicate that this flag
> can be used.
> 
> Thanks: Yaniv Kaul, Michal Skrivanek.
> ---
LGTM, just one note below.
> diff --git a/v2v/test-v2v-o-vdsm-options.sh
b/v2v/test-v2v-o-vdsm-options.sh
> index 3b7eaae..1de0e17 100755
> --- a/v2v/test-v2v-o-vdsm-options.sh
> +++ b/v2v/test-v2v-o-vdsm-options.sh
> @@ -21,6 +21,7 @@
>  unset CDPATH
>  export LANG=C
>  set -e
> +set -x
This should be left out, I guess.

Thanks,
-- 
Pino Toscano