Understand the average load on Linux and other UNIX-Like systems

Understand the average load on Linux and other UNIX-Like systems

"Load average" information can be displayed in Linux, Mac, and other UNIX-like systems. These numbers tell you how busy your system's CPU, hard disk, and other resources are. They seem hard to understand, but it is very easy to get familiar with them.

Whether you are using a Linux desktop or server, or a Linux-based router firmware, a network attached storage system based on Linux or BSD, or even a Mac OS X, you may see the "load average" Metric value anytime, anywhere.

Load VS average load

On UNIX-like systems, including Linux systems, the system load is used to evaluate how much work the system has performed, which is displayed in numbers. The average load of a completely idle computer is 0. Every running process, whether in use or waiting for CPU resources, will add 1 to the average load. Therefore, if the average load of your system is 5, five processes are in use or waiting for the CPU.

In traditional UNIX systems, only processes waiting for CPU are counted, but in Linux, processes waiting for other resources are also counted. For example, the process that is waiting to read and write the hard disk.

In itself, the load parameter does not mean anything. If some processes are using the CPU, the computer may load 0 at an instant, and 5 at another instant ,. Even if you know the number of loads at any given time, these numbers are basically meaningless.

This is why the UNIX-like system does not display the load at the current time. They use the average load-the average of Computer load over a few periods of time. These will tell you how much work your computer has actually performed.

View average load

The average load can be displayed on different graphics and terminal tools, including command lines and gnome system monitoring tools. In fact, the simplest and most standard way to view your average load is to run the "uptime" command on the terminal. This command shows the average load of your computer and the time when the computer has been enabled.

The uptime command can run in Linux, Mac OS X, or other UNIX-like systems. If your Linux or BSD-based device has a web interface, such as a DD-WRT routing firmware or NAS system, you may see average load information on the Status page.

Understand average load

At first glance, you see the average load, which seems completely meaningless. Below is an average load output example

Load average: 1.05, 0.70, 5.09

From left to right, these numbers show you the average load for the past 1 minute, past 5 minutes, and past 15 minutes. In other words, the above output indicates:

Average load in the past minute: 1.05

Average load in the past 5 minutes: 0.70

Average load in the past 15 minutes: 5.09

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