An ops vector is added in TLM to provide basic functionality from the archiving backend module. Currently only tar backend is supported. The ops vector facilitates replacing the backend with ZFS' or other backends.
After installing B7, ndmp.log was not created and the server couldnt be authenticated by the NBU client. There is a waitForLibraryReady() in the tlm_init which has lead to the hanging. The fix is already known for this issue.
See the comments