Comment 1 for bug 1587835

Issue orccours when:

delete_share_server_with_last_share = True
and
automatic_share_server_cleanup = True

I was able to reproduce with the following patch:
@@ -1878,11 +1879,15 @@ class ShareManager(manager.SchedulerDependentManager):
                 LOG.debug("Scheduled deletion of share-server "
                           "with id '%s' automatically by "
                           "deletion of last share.", share_server['id'])
+ print "Sleep some minutes....."
+ time.sleep(120)
+ import pdb; pdb.set_trace()
                 self.delete_share_server(context, share_server)

- @periodic_task.periodic_task(spacing=600)
+ @periodic_task.periodic_task(spacing=1)
     @utils.require_driver_initialized
     def delete_free_share_servers(self, ctxt):
         if not (self.driver.driver_handles_share_servers and
                 self.configuration.automatic_share_server_cleanup):