Problem Statement
What do the three numbers in load average represent?
Explanation
Load average shows the average number of processes in the run queue (ready to run or waiting for resources) over 1, 5, and 15 minute intervals. The uptime command displays these three numbers. For example, 'load average: 2.50, 1.80, 1.20' means 2.50 processes in queue over 1 minute, 1.80 over 5 minutes, and 1.20 over 15 minutes.
Interpret load average relative to CPU cores: on a system with 4 cores, load average of 4.0 means full utilization, below 4.0 means idle capacity, and above 4.0 means processes are waiting. A load of 8.0 on a 4-core system indicates significant queuing. Trending is important: increasing load suggests growing demand, decreasing load suggests stabilizing.
High load average indicates system stress from CPU-intensive processes, I/O wait (disk or network bottlenecks), or too many processes competing for resources. Use top, ps, or iostat to identify the cause. Understanding load average helps assess system health, capacity planning, and troubleshooting performance issues in production environments.
Practice Sets
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