[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [libvirt] [PATCH v4 2/4] storage: report error rather than warning if backing files doesn't exist



On Tue, Jul 16, 2013 at 10:47:54AM +0200, Martin Kletzander wrote:
> On 07/16/2013 10:40 AM, Daniel P. Berrange wrote:
> > On Tue, Jul 16, 2013 at 08:14:54AM +0200, Martin Kletzander wrote:
> >> On 07/15/2013 05:31 PM, Ján Tomko wrote:
> >>> On 07/02/2013 11:35 AM, Guannan Ren wrote:
> >>>> If one of backing files for disk source doesn't exist, the guest will not
> >>>> be able to find and use the disk even though the disk still exists in
> >>>> guest xml definition. So reporting an error make more sense.
> >>>>
> >>>> Adding virFileAccessibleAs() to check if the backing file described in
> >>>> disk meta exist in real path. If not, report error. the uid and gid
> >>>> arguments don't have so much meannings for F_OK, so give 0 for them.
> >>>> ---
> >>>>  src/util/virstoragefile.c | 23 +++++++++++++++--------
> >>>>  tests/virstoragetest.c    | 16 ++++++++--------
> >>>>  2 files changed, 23 insertions(+), 16 deletions(-)
> >>>>
> >>>> diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
> >>>> index 27aa4fe..cb61e5b 100644
> >>>> --- a/src/util/virstoragefile.c
> >>>> +++ b/src/util/virstoragefile.c
> >>>
> >>>> @@ -870,14 +877,10 @@ virStorageFileGetMetadataInternal(const char *path,
> >>>>                                         !!directory, backing,
> >>>>                                         &meta->directory,
> >>>>                                         &meta->backingStore) < 0) {
> >>>> -                    /* the backing file is (currently) unavailable, treat this
> >>>> -                     * file as standalone:
> >>>> -                     * backingStoreRaw is kept to mark broken image chains */
> >>>> -                    meta->backingStoreIsFile = false;
> >>>> -                    backingFormat = VIR_STORAGE_FILE_NONE;
> >>>> -                    VIR_WARN("Backing file '%s' of image '%s' is missing.",
> >>>> -                             meta->backingStoreRaw, path);
> >>>> -
> >>>> +                    VIR_ERROR(_("Backing file '%s' of image '%s' is missing."),
> >>>> +                              meta->backingStoreRaw, path);
> >>>> +                    VIR_FREE(backing);
> >>>> +                    goto cleanup;
> >>>>                  }
> >>>>              }
> >>>>              VIR_FREE(backing);
> >>>
> >>> This change means you won't be able to start the pool if one of the files is
> >>> missing a backing file. I've forwarded a patch [1] from/for [2] that ignores
> >>> missing files on pool start and there is a bug [3] requesting that we ignore
> >>> other files as well. I feel like this is going in the other direction.
> >>>
> >>> Wouldn't it be enough to check for them on domain start-up and leave the pool
> >>> running even if one of those volumes doesn't have an existing backing file?
> >>>
> >>
> >> How about making it configurable for the pool?  There are definitely
> >> some users who want the pool to reflect actual info after pool-refresh.
> > 
> > I don't think this needs to be configurable. The pool should show *every*
> > single file, regardless of whether the file has a broken backing file.
> > We shouldn't be trying to second guess what the user wants to do with a
> > image with broken backing file. Just expose as much info as we have and
> > let them deal with the problem.
> > 
> 
> I was thinking about the case that was mentioned in Jan's link to
> bugzilla, where they wanted to keep even deleted volumes.  Since I
> disagree with that for normal pool, we could make it configurable for
> such use-cases (although it looks more like invalid usage of our pools
> in that BZ).

Which BZ are you referring to ? I read BZ 977706 to be about not causing
errors during pool-refresh if a 2nd node has deleted the volume while
the first node is in the middle of refresh. This isn't about keeping
deleted volumes visible.


Daniel
-- 
|: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org              -o-             http://virt-manager.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]