what does load average mean

What does Load Average Mean?Have you ever wondered what \"load average\" means when you look at your system's performance metrics? In computing, load average is a term used to express the level of demand placed on a system's CPU over a certain period of time. This article will dive deeper into what load average is, how it is calculated, and what it means for your system's performance.

Understanding Load Average

Load average is a numerical value that represents the average number of processes that are actively running and waiting for CPU time. This value is usually expressed as a three-digit number, with each digit representing the load averages over the past 1, 5, and 15 minutes. For example, a load average of 0.50 means that there were, on average, half a process waiting for CPU time over the past 1-minute period.

Calculating Load Average

The load average calculation is based on a queue called the \"run queue,\" which contains processes that are ready to run but are waiting for available CPU resources. Over a specified time, the kernel tracks how many processes were on the run queue and calculates the average. This number can be used to determine how much work the system is currently doing compared to its capacity to handle that work.

Load Average vs. CPU Utilization

Load average and CPU utilization are often used interchangeably, but they are not the same thing. CPU utilization is a measure of how much work the CPU is doing at any given moment, while load average represents the amount of work that is waiting to be done. It is possible to have a high load average with a low CPU utilization if the majority of processes are waiting for I/O operations to complete.

Interpreting Load Average

Interpreting load average numbers can vary depending on the type of system and workload. As a general rule of thumb, a load average value of 1 or lower is considered normal, as it indicates that the CPU is keeping up with the workload. A load average of 2 or higher, however, suggests that the CPU is overloaded and may be struggling to keep up with the demand. In some cases, a sustained high load average can cause performance degradation, causing the system to become unresponsive or even crash.

Conclusion

In conclusion, load average is a crucial metric for understanding system performance, as it gives administrators an idea of how much demand the CPU is currently experiencing. By monitoring load average, you can proactively identify performance issues and take corrective action before they become a more significant problem. Now that you understand what load average is and how it is calculated, you can better manage your system's workload and optimize its performance.