Libguestfs - Jan 2011 - [PATCH] Display verbose error message when guest storage isn't found

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

On Wed, Jan 26, 2011 at 02:45:43PM +0000, Matthew Booth
wrote:
> 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);
ACK.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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