These are the procedures I followed for Ubuntu 14.04 LTS but should work with other Debian distros.
sudo fallocate -l 2G /swapfile sudo chmod 600 /swapfile sudo mkswap /swapfile sudo swapon /swapfile sudo swapon -s
Once you’ve done this you could make this permanent by editing the /etc/fstab file:
/swapfile none swap sw 0 0
If you’re using CentOS 7, Patrick in comments points out:
- The fallocate failed if you did not use ‘sudo’.
- the ‘swapon’ command failed on the root xfs, moved swap to ext works fine.