Create swap file
You will need to choose a location for your file. In this tutorial, it will be stored at the root of the server. We will create a 2GB swap file by running the following command:
dd if=/dev/zero of=/swapfile count=2048 bs=1M
dd command will produce output in a similar format to:
2048+0 records in 2048+0 records out 2147483648 bytes (2.1 GB) copied, 10.5356 s, 204 MB/s
Next, verify that the file is located at the root of your Vultr VPS by running:
ls / | grep swapfile
Proceed if you see the
Activate the swap file
Swap files are not recognized automatically. We will need to tell the server how to format the file and enable it so it can be used as a valid swap file. As a security measure, update the swapfile permissions to only allow R/W for root and no other users. Run:
chmod 600 /swapfile
The permission change can be verified by running the following command:
ls -lh /swapfile
You will see a file display:
-rw------- 1 root root 2.0G Oct 2 18:47 /swapfile
Next, tell the server to setup the swap file by running:
After running it, you will see the following output:
Setting up swapspace version 1, size = 2097148 KiB no label, UUID=ff3fc469-9c4b-4913-b653-ec53d6460d0e
If everything is shown as above, you are now ready to move on to the next step.
Turn swap on
Once your file is ready to be used as swap, you need to enable it by running:
You can verify that the swap file is active by running the
free command again.
free -m total used free shared buffers cached Mem: 1840 1754 86 16 23 1519 -/+ buffers/cache: 210 1630 Swap: 2047 0 2047
Swap shows something other than
0, then you have successfully setup swap.
Enable swap on reboot
By default, your server will not automatically enable this new swap file. To enable it on boot, you can update the
/etc/fstab file. Any text editor will suffice. In this example, I will be using
Add the following line at the end of the file:
/swapfile none swap sw 0 0
Save and close when you are finished editing the file. We are all done!