Solaris™ 8 Performance Tuning
James C. McPherson
When talking about tuning the performance of a UNIX system, sys admins
generally work through a number of concepts, such as the current perceived performance,
the difference between this level and a desired level of performance, the optimal
level claimed by the application vendor, how to measure performance differences,
and finally, what to tune and test.
The current perceived level of performance is based on what your users tell you and what you observe in your regular system monitoring. In a networked environment, if you have some users on the end of a 100-Mbit full-duplex connection, and others who are still using 10-Mbit half-duplex, then the 10-Mbit users will always tell you that the system is slow. However, you might have to wait for a serious application overload or resource crunch before the 100-Mbit users complain. There are also copious logfiles and measurable kernel statistics to facilitate system-level monitoring. Some sites also make use of tools such as CA UniCentre TNG, HP OpenView, or Sun’s SunMC to monitor via snmp MIBs. However, these are tools that must be used by competent systems and application administrators and should not be used alone.
The desired level of performance is somewhat different. Benchmarks are sometimes less than useful, but if you are using an application or system from a large vendor, they should have a specific benchmarking group that will replicate your environment and allow you to test realistic loads. You can trust a benchmark done in this manner because it is specifically tailored to your company’s requirements. If you don’t have the time or resources to organize a tailored benchmark, you’ll have to spend extra time doing it yourself. Before you get started, determine what measurements will be valid for your environment and how to obtain them. Also, work with your users in regard to when you can test tuning and monitoring.
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