Thank ypu to all who answered my earlier post.
The correct answer given to me was  256K (262144)

Here is a followup question.
Can this value also be used in W2K and W2K3 servers?
I seem to remember limitations in earlier versions of Windows/NetBackup.


>>> Bob Stump 11/15/2005 4:47 PM >>>
Because the data buffer size equals the tape I/O size, the value specified in 
SIZE_DATA_BUFFERS must not exceed the maximum tape I/O size supported by the 
tape drive or operating system. This is usually 256 KB or 128 KB.

For Digital Linear Tape (DLT) drives, the number that seems to give the best 
performance for SIZE_DATA_BUFFERS is 65536. Further performance improvements 
can be achieved by increasing the value in the NUMBER_DATA_BUFFERS file.

What is the optimum for STK 9940B?