Not that I am about to make a change on a Friday, but...

Has anyone followed the technote
How to enable Disk Staging Storage Unit (DSSU) duplication to tape using 
multiple tape drives 
http://seer.support.veritas.com/docs/278736.htm 

Is there a reason to increase the Max MPX for a disk based storage unit?
There is one known situation where the Max MPX values for a storage unit should 
be changed. This would occur when hundreds of jobs are being written 
simultaneously to disk based storage units. This will result in a pair of 
bpsched and bpjobd processes for each active job. The number of processes can 
consume resources on the master server and can also slow updates to the 
activity monitor in the GUI. Increasing the Max MPX setting for the disk 
storage units will allow multiple backup jobs to use one pair of bpsched and 
bpjobd processes and reduce the strain on system resources. This should only be 
used in situations where the backup performance or Activity monitor updates are 
slow.  

Bob Stump
State of Michigan