Can you please add steps to reproduce?
Not an easy reproduction, we had to stop the thread in the middle of the delete operation, restart Jboss in suspend JVM mode and verify it like that. Basically it can be reproduced (actually not reproduced in that case since the error is fixed) when you shutdown Jboss exactly when the result is returned from VDSM after a disk removal. I suggest moving to VERIFIED in that case since this is basically more of a code change
Following comment #2 and since we didn't face it lately with 3.5.5, moving to verified. In case we will reproduce we will reopen it.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2015-1938.html