Need a swap file on a Virtual Machine that didn’t come with one? Don’t care about the size, name or location? This is for you…

fallocate -l 1G /swap
chmod 0600 /swap
mkswap /swap
swapon /swap
echo "/swap none swap sw 0 0" >> /etc/fstab

I use lots of tiny virtual servers for development and testing and on most hosting providers they don’t come with a swap file by default. Sometimes I need a little more memory to get over a hump, such as installing or compiling software, but not for general operation so a bigger machine is overkill. I found lots of step-by-step guides online but I couldn’t find a full cut & paste script very easily online so I’ve posted one here.

Not for use in production, unless the size and location all happen to match your requirements.