StorageTek 6 manual Reduce Scheduling Contention, Usage Requirements, Syntax, Parameters

DETACHed from a virtual machine. This enables the volume to be available (that is, unselected) earlier than would otherwise be possible.

ACSPROP EXEC can also be used with VMOPERATOR to trap MOUNT messages for VMTAPE. LOGTABLE SAMPLE contains sample VMOPERATOR LOGTABLE statements to assist you. Consult VMOPERATOR documentation for information about tailoring the samples to your needs.

Syntax

ACSPROP

EXEC

Parameters

There are no external parameters required. The PROP interface to an EXEC action routine provides parameters in the program stack. These are documented in the VM description of PROP.

Usage Requirements

The only requirement is that the PROP ‘logical operator’ have a link to the MAINTSTK RUN-disk.

Reduce Scheduling Contention

Effective scheduling can increase library performance. Controlling the following scheduling related areas can help significantly in further increasing library performance:

•strive for a balanced workload

•schedule nonproductive library activities during low-demand times.

Balancing the Workload

If you experience higher than expected average mount times, but at the same time experience an improvement in production through-put, it could be an indication that your system is periodically flooded with work rather than having a balanced workload.

For example, all of your production jobs may be getting submitted at the beginning of a shift so that the library robots are overworked for the first few hours of the shift. Then, the robots may remain idle for the remainder of the shift. If you are using a scheduling software package and it releases jobs every hour on the hour, there may be tremendous tape transport contention for the first few minutes of each hour while the transports are unused for the remainder of each hour.

These situations tend to elevate average mount times; however, as long as the work is performed on time, there is probably no need to change conditions. However, if the work is not getting performed on schedule, you can improve performance by balancing your production workload.

426VM/HSC 6.0 System Programmer’s Guide

1st ed., 6/30/04 - 312579601