I think you also need to consider duty cycles - how much data does TSM push
per day, how hard will you be pushing the tape drives.

In my discussions with IBM & STK, they BOTH say that the LTO drives are not
designed to replace "enterprise class" drives, meaning the 3590's or 9840's.
The construction is just not designed to take the beating that the 3590's or
9840's are.   Which is why the drives are more expensive than LTO (DUH).
The 3590 & 9840 drives also have some performance characteristics that make
them faster than LTO for some operations (like dealing with a lot of
start/stop activity).   

This is neither good or bad.  It's a matter of matching your hardware to
your environment.

We have a TSM server here with some 9840 drives that run OVER 10 HOURS per
drive per day.  That is quite a beating.  Nothing short of a 9840 or 3590
will do. 

We have two other TSM environments that are much more sedate.   Those would
do fine with LTO.

Something else to consider.

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Wanda Prather
The Johns Hopkins Applied Physics Lab
443-778-8769
wanda_prather AT jhuapl DOT edu

"Intelligence has much less practical application than you'd think" -
Scott Adams/Dilbert
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