How to Disable Swap on Ubuntu Linux 20.04

(Updated )

Sometimes you need to disable Swap on a Linux server. For example, Kubernetes worker nodes need to have Swap turned off in order to increase the performance and stability. This tutorial will show you how to disable Swap on a Ubuntu Linux server.

Check if Swap is enabled

First check if swap is enabled:

sudo swapon --show

If swap is enabled you should see the path to the swap file and its size.

ubuntu@kube03:~$ sudo swapon --show
NAME      TYPE SIZE USED PRIO
/swap.img file 1.9G 4.5M   -2

You can also check by running the free command:

free -h

The Swap line should show the total size and how much is used.

ubuntu@kube03:~$ free -h
              total        used        free      shared  buff/cache   available
Mem:          952Mi       211Mi       124Mi       1.0Mi       617Mi       582Mi
Swap:         1.9Gi       4.0Mi       1.9Gi
ubuntu@kube03:~$

Disable Swap

Run the following command to disable Swap:

sudo swapoff -a

Now remove the Swap file:

sudo rm /swap.img

The next thing we need to do is modify the fstab file so that the Swap file is not re-created after a system reboot.

Remove following line from /etc/fstab

/swap.img       none    swap    sw      0       0

Check Swap is disabled

Run the following command to check Swap is disabled.

sudo swapon --show

There should be no output if it’s disabled.

Conclusion

This tutorial showed you how to disable Swap, remove the old Swap file and make sure Swap is disabled after your system restarts.

Ubuntu