What does load average mean?
The “load average” of the UNIX system is the average number of processes assigned to the specified processor set that are in the system run queue, averaged over various periods of time. For example, your UNIX system may have 100 processes in the process table, but at a given moment, 98 of them may be “sleeping”, such as a web server which just “sleeps” while waiting for a web browser to connect to it. These processes use no CPU time while they “sleep”, so a single-CPU system will spend all of its time flipping (“context switching”) between the two “running” processes, giving each a little slice of processing time before switching back to the other. The subset of a UNIX system’s processes which are actually “running” make up the “run queue”. If three processes are running, and are all demanding the full CPU’s time, each will have to share the CPU’s time with the other processes, and thus the average number of processes in the run queue will be about 3.0. If there is only one process “ru
