Identifying and resolving common performance problems

 

Many different performance problems often affect common areas of the system. Learn how to research and resolve problems in common areas, for example, backup and recovery.

When performance problems occur on the system, they often affect certain areas of the system first. Refer to the following table for some methods available for researching performance on these system areas. Many of these areas are available as system monitor metrics. However, there are several other ways to access information about them.

Area Description Available tools
Processor load Determine if there are too many jobs on the system or if some jobs are using a large percentage of processor time.

  • Work with Active Jobs (WRKACTJOB) command.

  • Work with System Activity (WRKSYSACT) command, which is part of Performance Tools licensed program.

  • The work management function in iSeries™ Navigator.

  • CPU utilization metrics within the iSeries Navigator system monitor.

  • Work with Disk Status (WRKDSKSTS) command.
Main storage Investigate faulting and the wait-to-ineligible transitions.

  • Disk storage metrics within the iSeries Navigator system monitor.

  • Work with System Status (WRKSYSSTS) command.

  • The Memory Pools function under Work Management in iSeries Navigator.
Disk Determine if there are too few arms or if the arms are too slow.

  • Work with Disk Status (WRKDSKSTS) command.

  • Disk arm utilization metrics within the iSeries Navigator system monitor.

  • Performance Tools System and Component report.
Communications Find slow lines, errors on the line, or too many users for the line.

  • Performance Tools Component Report.

  • LAN utilization metrics within the iSeries Navigator system monitor.
IOPs Determine if any IOPs are not balanced or if there are not enough IOPs.

  • Performance Tools Component Report.

  • IOP utilization metrics within the iSeries Navigator system monitor.
Software Investigate locks and mutual exclusions (mutexes).

  • Performance Tools Locks report.

  • Performance Tools Trace report.

  • Work with Object Locks (WRKOBJLCK) command.

  • In iSeries Navigator, right-click the suspect job under Work Management, and select Details > Locked Objects.

  • Work with System Activity (WRKSYSACT) command.

  • Display Performance Data (DSPPFRDTA) command.
Backup and recovery Investigate areas that affect backup and recovery and save and restore operations.

  • iSeries Performance Capabilities Reference (Save/Restore Performance chapter).

  • Why does my backup take so long after I restart my server?

  • Why do my backups take longer after I upgrade to a new release?

  • Why do my backups take longer after I change hardware on my server?

 

Parent topic:

Researching a performance problem

Related concepts
Work management

Related reference
Monitor metrics Backup and recovery frequently asked questions
Related information
System i Performance Capabilities Reference (Save/Restore Performance chapter)