Troubleshoot slow backups

Hi 

I have an AIX netbackup envt with db2 backups some which are san media servers and others just clients.

I wnat to check  logs which i can look at and also tuning parameters in order to try and improve backup speed.

From Media server i know i can check teh bptm logs. Any other logs that will provide insight and what are the tuning parameters I can look into ?.

Thanks in advance.