Comment 0 for bug 1779826

When deleting the image of an instance of the SHELVED_OFFLOADED state and then executing the unshelve instance operation, the unshelve instance fails, but there is no corresponding error message in the fault table of the target instance.

You can reproduce the bug by following the steps below：
1.Create an instance in your environment, named "instance01", then do "Shelve Instance";
2.The first step, if executed successfully, will generate an image named "instance01-shelved", select and delete it;
3.Return to the instance list, find the target instance, and then do "Unshelve instance". The status of this
  instance will be set to Error, but there is no error message in the instance fault table.

I think that I have seen an error in the instance, but I don’t know why it is wrong. This is unfriendly.