Complete workload measurement on a production system

The techniques of measurement on production systems are similar to those on dedicated systems, but we must be careful to avoid degrading system performance.

Probably the most cost-effective tool is the vmstat command, which supplies data on memory, I/O, and CPU usage in a single report. If the vmstat intervals are kept reasonably long, for example, 10 seconds, the average cost is relatively low. See Performance-Limiting Resource identification for more information on using the vmstat command.