[Libguestfs] [PATCH] Display verbose error message when guest storage isn't found

[Matthew Booth]

Unfortunately libvirt will not always return volume information for a guest's
volume. Specifically, it will not return volume information if the volume is not
in a storage pool. Rather than displaying a generic libvirt error in this case,
advise the user how they can create an appropriate storage pool.

Fixes RHBZ#672498
---
 lib/Sys/VirtV2V/Connection/LibVirtSource.pm |   27 +++++++++++++++++++++++----
 1 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/lib/Sys/VirtV2V/Connection/LibVirtSource.pm b/lib/Sys/VirtV2V/Connection/LibVirtSource.pm
index 628074c..9db9f60 100644
--- a/lib/Sys/VirtV2V/Connection/LibVirtSource.pm
+++ b/lib/Sys/VirtV2V/Connection/LibVirtSource.pm
@@ -130,10 +130,29 @@ sub get_volume
         eval {
             $vol = $self->{vmm}->get_storage_volume_by_path($path);
         };
-        die(user_message(__x("Failed to retrieve storage volume {path}:".
-                             "{error}",
-                             path => $path,
-                             error => $@->stringify()))) if($@);
+        if ($@->code == Sys::Virt::Error->ERR_NO_STORAGE_VOL) {
+            die user_message(__x("Failed to retrieve volume information for ".
+                                 "{path}. This could be because the volume ".
+                                 "doesn't exist, or because the volume exists ".
+                                 "but is not contained in a storage pool.\n\n".
+                                 "In the latter case, you must create a ".
+                                 "storage pool of the correct type to contain ".
+                                 "the volume. Note that you do not have to ".
+                                 "re-create or move the volume itself, only ".
+                                 "define a pool which contains it. libvirt ".
+                                 "will automatically detect the volume when ".
+                                 "it scans the pool after creation.\n\n".
+                                 "virt-manager is able to create storage ".
+                                 "pools. Select Edit->Connection Details ".
+                                 "from the application menu. Storage pools ".
+                                 "are displayed in the Storage tab.",
+                                 path => $path));
+        } else {
+            die user_message(__x("Failed to retrieve storage volume {path}:".
+                                 "{error}",
+                                 path => $path,
+                                 error => $@->stringify()));
+        }
 
         ($name, $format, $size, $usage, $is_sparse, $is_block) =
             parse_libvirt_volinfo($vol);
-- 
1.7.3.5