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How to enable swap on Linux

To enable swap permanently on Linux, you can follow these steps:

1. Create a swap file or partition: If you haven't already created a swap file or partition, you can use the fallocate command to create a swap file of a desired size. For example, to create a 2GB swap file, you can use the following command:

sudo fallocate -l 2G /swapfile

1. Change the permissions of the swap file: You should change the permissions of the swap file to only allow root to read and write to it. You can use the chmod command to do this:

sudo chmod 600 /swapfile

1. Format the swap file: You should format the swap file as a swap area using the mkswap command:

sudo mkswap /swapfile

1. Add the swap file to the system: To enable the swap file permanently, you need to add it to the system's /etc/fstab file. Open the file in a text editor with sudo privileges:

sudo nano /etc/fstab

1. Add the following line at the end of the file to mount the swap file on boot:

/swapfile none swap sw 0 0

Save and close the file.

1. Enable the swap file: To enable the swap file immediately, you can use the swapon command:

sudo swapon /swapfile

You can verify that the swap file has been enabled by running the free command:

free -h

This command should show the amount of swap space available in addition to the system's RAM.