How to enable SWAP on your server

Introduction

If you wish to enable swap on your server, there are a handful of methods that can be used. The below examples assume you are using CentOS or RedHat RHEL OS.

Procedure

For CentOS:

Using example swap mount point: /root/cp-swap

Commands (run as root):

fallocate -l 2G /root/cp-swap
ls -al /root/cp-swap 
mkswap /root/cp-swap 
swapon /root/cp-swap 

Verify swap is enabled by running this command.

Command:

free -mh

How to check available swap space on your server.

To make the change permanent, add the following line to your /etc/fstab file.

Add line to /etc/fstab file:

/root/cp-swap swap swap defaults 0 0

Please use extreme caution when modifying the /etc/fstab file. It is responsible for the mounting of the partitions on the server. If unfamiliar with the file, we would recommend having a qualified System Adminstor make the change.

Where do I find a system administrator?

For RedHat RHEL OS:

RedHat has multiple ways of enabling swap. Please refer to their documentation for instructions.

RedHat - Swap Space