Correcting for printer performance issues – MVS
Table F-11. Components to check for printer performance problems
On the MVS system, ensure that both the PSF and TCP/IP address spaces are receiving
a high level of service, are at a high dispatching priority, and their datasets and the JES2
spool datasets are on DASD volumes that have low competing activity from other
applications and from other DASD volumes on the same path.
Ensure that the Maximum Transmission Unit size (MTU) is as large as possible. A small
MTU size increases the number of packets that are transmitted, allowing greater chances
of degradation throughout the network. Increasing the MTU size in both TCP/IP for MVS
and in the printer may improve printer performance.
If the printer is on a LAN that also has a large number of other devices attached to it, the
high levels of traffic on the LAN can cause printer speed degradation. Consider moving
the printer to a LAN that does not have so much activity on it.
If the speed of the link connecting the LAN with the printer attached to the MVS system is
slow, this could be a bottleneck. This could be a concern with any configuration in which
the LAN-attached controller (i.e., 3745, 3172, or 3174) is not directly channel-attached to
the host running PSF. This could occur in a Remote LAN configuration as discussed in the
Network Configurations section, earlier in this chapter. Review your network configuration
diagrams to look for any potential bottlenecks.
Installation Planning Guide
– The default MTU value in the printer is 2052. To change
the MTU size for the printer, refer to the Sun network
– If these items are all in order, consult your network
administrator about a possible network problem.
Should you notice any printer performance problems—e.g.,
through-put speed degradation, check the areas listed in the