Setting Ubuntu Swap File

To increase the swap file size on an Ubuntu system using fallocate , follow these updated instructions. This method is efficient and quick, suitable for most modern filesystems.

Step 1: Turn Off Existing Swap File

Disable the currently active swap file to modify or replace it:

sudo swapoff -a

This command turns off all swap spaces in use.

Step 2: Create or Resize the Swap File with fallocate

Use fallocate to allocate space for the swap file instantly:

sudo fallocate -l 4G /swapfile

• -l 4G specifies the desired size of the swap file, 4GB in this example.
• /swapfile is the file to be used or created for swap.

Adjust the size ( 4G in the example) according to your needs.

Step 3: Secure the Swap File

Set the swap file's permissions to ensure it is only accessible by the root user:

sudo chmod 600 /swapfile

This command restricts access to the swap file, enhancing security.

Step 4: Make the Swap File

Format the newly created file for use as swap:

sudo mkswap /swapfile

This prepares the swap file for use by setting it up as a swap space.

Step 5: Activate the Swap File

Enable the swap file, adding it to your system's swap space:

sudo swapon /swapfile

This step makes the swap file active, allowing the system to use it.

Step 6: Make the Swap File Permanent

Edit /etc/fstab to include the swap file for automatic activation at boot time:

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

Appending this line to /etc/fstab ensures the swap file is recognized and activated at every startup.

Step 7: Verify the Swap File

Check that the swap is active and verify its size:

sudo swapon --show

To see the total available swap space, including the newly added swap:

free -h

This concludes the steps to increase the swap file size on your Ubuntu system using fallocate . Adjust the swap file size in step 2 as necessary to suit your system's requirements.