Not so bad IBM article about...

...Tivoli Storage Manager Client Incremental Backup Memory Requirements

TSM LTO-3 Performance Settings

I just got this info from our architect who attended an IBM tape seminar. It was stated during the seminar that to get peak performance out of LTO-3 in TSM you need to set the following parameters:

These apply to TSM 5.3

• TXNBytelimit       2GB


• TXNGroupmax     65000


• MOVESizethres    2GB


• MOVEBatchsize   1000

I have heard of some issues with using the full 65000 on the TXNGroupmax setting, but if you want best performance these settings need to be used.