Show Table of Contents
20.2. Viewing Memory Usage
20.2.1. Using the free Command
The
free command allows you to display the amount of free and used memory on the system. To do so, type the following at a shell prompt:
free
The
free command provides information about both the physical memory (Mem) and swap space (Swap). It displays the total amount of memory (total), as well as the amount of memory that is in use (used), free (free), shared (shared), sum of buffers and cached (buff/cache), and available (available). For example:
~]$ free
total used free shared buff/cache available
Mem: 1016800 727300 84684 3500 204816 124068
Swap: 839676 66920 772756
By default,
free displays the values in kilobytes. To display the values in megabytes, supply the -m command line option:
free-m
For instance:
~]$ free -m
total used free shared buff/cache available
Mem: 992 711 81 3 200 120
Swap: 819 65 754
For a complete list of available command line options, see the free(1) manual page.
20.2.2. Using the System Monitor Tool
The Resources tab of the System Monitor tool allows you to view the amount of free and used memory on the system.
To start the System Monitor tool from the command line, type
gnome-system-monitor at a shell prompt. The System Monitor tool appears. Alternatively, if using the GNOME desktop, press the Super key to enter the Activities Overview, type System Monitor and then press Enter. The System Monitor tool appears. The Super key appears in a variety of guises, depending on the keyboard and other hardware, but often as either the Windows or Command key, and typically to the left of the Spacebar.
Click the Resources tab to view the system's memory usage.
Figure 20.2. System Monitor — Resources
In the Memory and Swap History section, the System Monitor tool displays a graphical representation of the memory and swap usage history, as well as the total amount of the physical memory (Memory) and swap space (Swap) and how much of it is in use.
Where did the comment section go?
Red Hat's documentation publication system recently went through an upgrade to enable speedier, more mobile-friendly content. We decided to re-evaluate our commenting platform to ensure that it meets your expectations and serves as an optimal feedback mechanism. During this redesign, we invite your input on providing feedback on Red Hat documentation via the discussion platform.