An SAP instance runs within an operating system. The operating system provides the instance with the following resources:

• Virtual memory
• Physical memory
• CPU
• File system management
• Physical disk
• Network

Bottlenecks in these areas can significantly affect the performance of the SAP system. You can monitor these resources using the CCMS operating system monitor.

The operating system monitor helps you locate the cause of a performance problem. If the source of the problem is in the operating system, you can analyze it further and resolve it using external tools or other external means.

Performance indicators are:

• Average load of and utilization of the CPU
• Memory utilization
• Paging in and out of data to and from the memory (replaced by pool data in the OS/400 operating system monitor)
• Disk utilization information
• LAN activity
• Operating system configuration parameters