How to read this

[Bob Blunt]

Douglas, let's step back a bit... All the answers you've gotten have been valid and valuable. However all the basics have been skipped and you may have been handed a bag of snakes. Good for you that you're interested because you can build your knowledge using the investigation. There are some points of information that would make it easier for your research and general knowledge and for us to help you.

OpenVMS Version?
Hardware type (VAX/Alpha/Integrity/emulated)?
What type disk controllers?
How are they connected to the system?
How are the tape units connected?

You might ask "Why are these important to solve our problem?"

No operating system that receives regular updates is static and utilties are changed to (hopefully) make them work more efficiently and correctly. So knowing your version of OpenVMS is the most critical. Hardware configuration can be important because, to use a car analogy, a Chevette can't usually run as fast as a CORvette or haul as much as a tractor-trailer. So if your "problem" system is a workstation class system you get one performance expectation and a large system should run much differently. Configuration of your peripherals can also affect the operation of your system so knowing how it goes together helps you, and us, know where to look for bottlenecks.

All the previous replies have good suggestions. You'll need to combine all that into a concise solution to evaluate what factors are combining to cause the differences in the ways you're seeing your NetBackup jobs run.

Some general things you can check on OpenVMS *when* you see slow performance are:

SHOW USERS
SHOW SYSTEM
SHOW QUEUE/FULL/ALL
SHOW ERROR
SHOW MEMORY

I'm not familiar enough with NetBackup to tell you that there's a potential for slowdown due to, for example, network activity. If other jobs are running and your OpenVMS system is sharing it's disk and tape connection over a SAN fabric of some sort then the OpenVMS NetBackup jobs could easily be affected by workload induced by or on other systems sharing the SAN. If, however, your system is using directly connected disk (via SCSI for example) and tapes then the factors that are affecting the performance of the NetBackup jobs *should* only be limited to activity on the VMS system(s) and possibly the network (if NetBackup depends on community Ethernet for instance/example).

There's a LOT to be learned but it can be a fascinating process...

bob