I have the exact same issue, discovered it after i restarted the server today. I dont really keep track of the updates i apply but i know Docker was updated the other week and i 'think' i received a kernel update as well.
OMV 3.0.95, kernel Linux 4.9.0-0.bpo.4-amd64 and Docker 17.12.0-ce.
Do you still have this issue? I believe it should have been fixed now (the URL to the looks to be corrected).