Windows 2000 Performance Guide

Memory Capacity Planning

The previous sections of this chapter discussed the manner in which Windows 2000 manages real memory and the performance statistics that describe what is happening to both process virtual memory and physical RAM on a Windows 2000 system. With this background, we can now move on to tackle a more demanding set of questions. This section discusses Windows 2000 server and workstation memory capacity planning. How can you tell when a system needs more RAM? When is a system undergoing excessive paging? Finally, how can you forecast demand for RAM so that you can stay ahead of your hardware requirements?

Measuring Memory Utilization

We have seen that Windows 2000 reports two types of memory utilization statistics. It reports several instantaneous measures of real memory allocation (Available Bytes, Cache Bytes, per-process Working Set Bytes), and several indicators of virtual memory management-oriented paging activity (Transition Faults/sec, Page Reads/sec, Page Writes/sec, and Demand Zero Pages/sec). In this section, we further explore the relationship between memory allocation and paging activity, with an eye to interpreting the measurement data available in Windows 2000. In particular, we want to be able to detect when a Windows 2000 system is paging too much and needs more memory. By monitoring hard page fault rates, for instance, you should be able to identify Windows 2000 systems that are paging excessively. In this section, we provide an illustration of a ...