Hello,
> Christian - Please post error indications or other evidence which
 >           support this being a problem you're seeing, and why it
> appears to be a problem.
>  thanks, Richard

So I try to explain a little more.
We use a TSM solution with primary on disk and copy on 1 drive library (3581 in 
this case).
It allows TSM solutions on small sites with near the same reliability and 
efficiency than big ones.
Each monday we put in empty tapes.
Each day, an incremental copy is made on tape (LTO1 100Go).
Each incremental is made of (we suppose) 1 big BRMS file (70 Go, no 
incremental, no compression) and a lot of small windows files (5Go for the 
whole). 
Fisrt day, 25% remains free on tape 1
But the second day, TSM does't use these 25%, but again 75% on tape 2, and so 
on for the following days.
It seems as if TSM begins with the BRMS file, can't split it, takes the next 
tape, writes the BRMS file and continues with small files. 
We would like to understand why, in this case, TSM doesn't split file because 
we get only a 75% filling.
2 possible reasons we see are :
- TSM doesn't know how to split "BRMS files" (but file is already on disk, it's 
"no more" really a BRMS file ?)
- TSM doesn't support file splitting with 3581 (1 drive) ?
If somebody has an idea, thanks.  

Best regards

Christian Bagard
c.bagard AT sos-restore DOT com
SOS-Restore - 32 cours Mirabeau - 13100 Aix-en-Provence - France