System information

General Notes on System Tuning 5
analysis, the Linux kernel offers means to perform such analysis. See PartIII, “Kernel
Monitoring” (page69) for coverage.
Once you have collected the data, it needs to be analyzed. First, inspect if the server's
hardware (memory, CPU, bus) and its I/O capacities (disk, network) are sufficient. If
these basic conditions are met, the system might benefit from tuning.
1.4 Step-by-step Tuning
Make sure to carefully plan the tuning itself. It is of vital importance to only do one
step at a time. Only by doing so you will be able to measure if the change provided an
improvement or even had a negative impact. Each tuning activity should be measured
over a sufficient time period in order to ensure you can do an analysis based on sig-
nificant data. If you cannot measure a positive effect, do not make the change perma-
nent. Chances are, that it might have a negative effect in the future.