We have just purchased a bunch of 3592JB tapes (700GB uncompressed capacity) to 
use for some large NDMP backups. My first test last night backing up around 
1.8TB of data completely filled two of these tapes. This is only marginally 
better than what I was getting on the 3592JA tapes which are rated at 300GB 
uncompressed.  We have 8 TS1120 (3592-E05) drives in a 3494 library and are 
running TSM 6.1.3.4.  The device class specifies FORMAT=DRIVE which should 
cause recording at the highest available density. I would think almost all of 
this data would fit on one of these volumes.  Any ideas where I am going wrong?

Thanks
Sam Sheppard
San Diego Data Processing Corp.
(858)-581-9668