How to create a swapfile in Lubuntu 20.04 & 20.10

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How to create a swapfile in Lubuntu 20.04 and 20.10

1.Check to see if the system has any swap configured :

$ swapon --show

If you receive no output this means the system has no swapfile available

To verify this run the following command:

$ free - h

2. In the case that a previous swapfile is on your system you need to run the following 2 commands - otherwise continue on to step 3

a. To turn off swap:

$` sudo swapoff -a` 

b. Then remove the swapfile:

$` sudo rm -i  /swapfile`

3. In this example we create a 8GB swapfile (in general double your RAM -please note that I am using 8 GB only as an example)

   $ sudo dd if=/dev/zero of=/swapfile bs=1M count=8192
   

   

   Set file protections:

   $ sudo chmod 600 /swapfile
   Verify the permissions:

   $ ls -lh /swapfile

   

   We can see that only root user has the read and write flags enabled.

   Mark the file as swap space by typing:

   $ sudo mkswap /swapfile

   We then enable the swap file:

   $ sudo swapon /swapfile

   Verify that the swap is available and confirm 4 GB RAM and 8 GB swap by typing:

   $ free -h

   

4. Make the swap file permanent
   Back up the /etc/fstab file in case thing goes wrong:

   $ sudo cp -pv /etc/fstab /etc/fstab.bak

5. Edit /etc/fstab

   $ sudo vim /etc/fstab (or your favorite text editor)

Add this line in /etc/fstab and confirm that there are no other “swap” lines
/swapfile none swap sw 0 0

6. Reboot the system and verify the operation

   $ free -h