We have the IBM 6157-002 tape streamer which should be able to back up 150 MB on (a 150 MB of course) one tape. But for some reason we have never been able to get more than about 30 or 45 MB on one tape. Can anyone tell what we're doing wrong? Maybe the density must be given, but what densitiy? Peter Mutsaers, nmutsaer at ruunsa.fys.ruu.nl