GoOnline

Add Swap Space on Ubuntu 22.04

October 08, 2022

Check Swap Information

sudo swapon --show

Verify that there is no active swap using the free utility:

free -h
Output
                total        used        free      shared  buff/cache   available
Mem:            15Gi       2.6Gi       7.5Gi       821Mi       5.3Gi        11Gi
Swap:          2.0Gi          0B       2.0Gi

Check Available Space on Hard Drive

df -h
Output
Filesystem      Size  Used Avail Use% Mounted on
tmpfs           1.6G  2.3M  1.6G   1% /run
/dev/nvme0n1p2  234G   24G  198G  11% /
tmpfs           7.7G  155M  7.6G   2% /dev/shm
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
/dev/nvme0n1p1  511M  5.3M  506M   2% /boot/efi
tmpfs           1.6G  8.2M  1.6G   1% /run/user/1000

The device with / in the Mounted on the column is our disk in this case.

Creating a Swap File

The best way of creating a swap file is with the fallocate program. This command instantly creates a file of the specified size.

sudo fallocate -l 1G /swapfile

Verify this by using:

ls -lh /swapfile
-rw------- 1 root root 2.0G اگست   23 09:28 /swapfile

Enable Swap File

Make the file only accessible to root by typing:

sudo chmod 600 /swapfile

Verify by using this:

ls -lh /swapfile
-rw------- 1 root root 2.0G اگست   23 09:28 /swapfile

We can now mark the file as swap space by typing:

sudo mkswap /swapfile
Setting up swapspace version 1, size = 2048 MiB (1073737728 bytes)
no label, UUID=6e965805-2ab9-450f-aed6-577e74089dbf

After marking the file, we can enable the swap file, allowing our system to start using it:

sudo swapon /swapfile

Verify that the swap is available by using:

sudo swapon --show
NAME      TYPE SIZE USED PRIO
/swapfile file   2G   0B   -2

Now check again output of thefree utility 

free -h

Make Swap File Permanent

Back up the /etc/fstab file in case anything goes wrong:

sudo cp /etc/fstab /etc/fstab.bakcup

Add the swap file information to the end of your /etc/fstab file by typing:

echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab