Evaluating platform statistics

Using Perfmon on Windows™ systems

If you use Perfmon on Microsoft™ Windows™, some counters may report inaccurate information because of the way that Perfmon collects statistics. Logical disks that are actually very busy may report average queue lengths of zero. Unplugged network adapters may show traffic.

Network statistics

On IBM® AIX®, Linux™, Linux™ on z/Series and IBM i®, Domino® provides statistics for a maximum of ten network adapters. On Microsoft™ Windows™, there is no limit on the number of network adapters. The loopback interface is not included in the list of adapters. On AIX®, only Ethernet and token ring network adapters are supported.

Process statistics

On Microsoft™ Windows™, when you view process statistics, the Percentage Total Domino® CPU Utilization value may be greater than the Total System CPU Utilization. This is because the CPU utilization value for each individual process is calculated based on the total number of processes used in a sampling interval.

On Windows™, Domino® process names include the letter "n" as a prefix. For example, in Perfmon, Adminp -- the process name for the Administration Process -- is nadminp. To maintain platform-independence in naming, Domino® does not include the prefix on any platform statistics.

On IBM® AIX®, IBM i®, and Linux™ platforms, process statistics indicate how busy the processes are, but these are not absolute values. On these platforms, the utilization is based on how busy the processes are in the current sampling period as compared to how busy they were in the previous sampling period. For example, if a process reports 30% utilization in the first sampling and 60% in the second, the process is twice as busy.

On all platforms, by default, the performance statistics for processes that are idle have the value zero.

Logical disk statistics

On Microsoft™ Windows™ the values for disk utilization counters may exceed 100%, indicating that the disks are being heavily utilized. Similarly, on multiprocessor systems, the individual CPU utilization for a process may exceed 100%, depending on the number of processors in the system.

On IBM i®, there are statistics for a maximum of ten logical disks (auxiliary storage pools).

System statistics

On Microsoft™ Windows™ the value of the combined CPU utilization statistic (Platform.System.PctCombinedCpuUtil) is not defined as sum of the user and privileged CPU utilization values (Platform.PctUserCpuUtil and Platform.PctPrivilegedCpuUtil). However, on Linux™, Linux™ for IBM® i, and IBM® AIX®, the value of the combined CPU utilization statistic is defined as sum of the user and privileged CPU utilization values.