swapon:tldr:0dcc5

The "swapon -a" command is used to activate all swap devices mentioned in the "/etc/fstab" file.

In Linux, swap space is used as a temporary storage area that allows the system to move idle processes or parts of the active memory (RAM) to the disk when the RAM becomes full. The swap space helps increase the overall system performance and prevents the system from running out of memory.

Here's how the command works:

• "swapon" is a command-line utility used to enable swapping on a particular device or file.
• The "-a" option is used to enable swap on all devices specified in the "/etc/fstab" file.
• The "/etc/fstab" file is a configuration file that lists all the file systems and swap devices that should be automatically mounted at system startup.

When you execute the "swapon -a" command, it checks the "/etc/fstab" file for entries related to swap devices and activates them. This ensures that all defined swap spaces are available for use by the system.