Swapping or swap space refers to a physical memory page located on a disk partition or special file, used for extending the available RAM of a system when physical memory becomes full.

Through this approach to expanding RAM capabilities, inactive memory pages are commonly moved into the swap area once RAM is exhausted. However, due to the rotational speed limitations of traditional hard drives, swap performance in terms of data transfer and access times is significantly slower than that of RAM.

On modern systems equipped with high-speed SSDs, allocating a small swap partition can substantially improve access speeds compared to conventional HDDs, although it still remains far behind RAM in terms of performance.

Some recommend setting swap space to double the size of installed RAM. On systems with more than 4 GB RAM, however, swap should be set between 2 and 4 GB.

If your server has sufficient RAM or does not benefit from using swap space—or if swapping noticeably harms system performance—you may want to consider disabling the swap area.

How to Check Swap Space in Linux

Before proceeding with disabling swap, first assess your current memory usage and locate the swap partition by executing the following free command:

<code># free -h </code>

Check the Swap section for "used" space. If the used value is 0B or nearly zero, then it’s safe to assume that swap isn't being actively used and can be disabled.

How to Check Swap Partition in Linux

Next, run the blkid command, and look for TYPE="swap" to identify the swap partition, as shown below.

<code># blkid </code>

Also, execute the lsblk command to find the [SWAP] partition as demonstrated below.

<code># lsblk</code>

How to Disable Swap in Linux

Once you've identified the swap partition or file, use the following command to turn off the swap space.

<code># swapoff /dev/mapper/centos-swap  </code>

Alternatively, disable all swaps listed in /proc/swaps using:

<code># swapoff -a </code>

Run the free command again to confirm swap has been turned off.

<code># free -h</code>

How to Disable Swap Permanently in Linux

To permanently remove swap support in Linux, edit the /etc/fstab file, locate the line referencing swap, and comment it out by placing a # at the beginning, as illustrated below.

<code># vi /etc/fstab</code>

Then, reboot the machine to apply changes, or in some cases, run mount -a.

<code># mount -a</code>

After rebooting, re-run the commands introduced earlier in this guide to verify that swap has been fully and permanently removed.

<code># free -h
# blkid 
# lsblk </code>

You might also like:

• How to Add Swap Space on Ubuntu Linux
• How To Create a Linux Swap File
• How to Clear RAM Memory Cache, Buffer, and Swap Space on Linux
• How to Monitor Swap Space Usage in Linux

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