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====== How To Create a New Swap File ======

Sometimes the amount of RAM that your system has is not enough for the applications you run, or maybe you're running some poorly-written software that runs fine within the RAM you have but complains about low amounts of swap space. In either case, you'll need to add more "swap" space - also known as "virtual memory" - to your system.

The guide below will demonstrate how to do this. We will be moving forward with the following assumptions (both of which will be up to you to decide):
  * You want your new swap file to be ''%%16GB%%'' in size.
  * You wish to create the swap file at ''%%/var/cache/swap/swapfile%%''.

===== Create the Swap File =====

The first thing you need to do is create the swapfile (obviously!). Simply create the directory (if it doesn't already exist), then use ''%%fallocate%%'' to create your new swap file:

<code>
mkdir -p /var/cache/swap
fallocate -l 16G /var/cache/swap/swapfile
</code>

===== Configure the Swap File =====

Now we need to set permissions on the swap file so that only root can read/write to it. Simply run:

<code>chmod 600 /var/cache/swap/swapfile</code>

And then run ''%%mkswap%%'' to create the swap space:

<code>mkswap /var/cache/swap/swapfile</code>

At this point, we have a swap file located at ''%%/var/cache/swap/swapfile%%'' that is 16GB in size and is ready to go.

===== Enable the Swap =====

Finally we need to configure our system to load the swap at boot time, and then load the swap space on our running system (or just reboot, either works). Open up ''%%/etc/fstab%%'' in your preferred text editor, and either 

<code></code>

Now you can either reboot to load the new swap space, OR you can run the following command to load it on the running system:

<code>swapon /var/cache/swap/swapfile</code>

===== Testing =====

Of course, anything you do is worth testing. To do that, simply run ''%%free -m%%'' to show your system's memory usage. You should see something like the picture below:

// Pic

Obviously your system stats will look different than mine do depending on the configuration of your system, but you should see a total virtual memory figure that resembles 16GB (16384MB) of virtual memory, or at least whatever amount of space you decided to give to it.

Also note that if you just ran the ''%%swapon%%'' command instead of rebooting and you're migrating from one swap file to another, you may see the total size of the two swap files. To correct this, simply run ''%%swapoff </path/to/old/swapfile%%'' and you should see a total virtual memory that corresponds to your new swap file.