Joined: 03 Oct 2009 Posts: 1783 Location: Bloomington, IL
It would have helped if you'd mentioned that the message number is IEF462I. Fortunately, we don't have to depend on you for information.
Note that a relative generation number of (+0) means the current generation. You probably blindly requested a concatenation of generation data sets that required more tape drive than were available in the esoteric unit; or perhaps one or more data sets were miscataloged.