Auto restart server if virtual memory is too low

1. Check how much memory is left on the VPS.
2. If 500M memory is left , reboot the VPS.

This could be done as follow

1. Write a script that checks how much memory is left and reboot the VPS
2. Add this script to crontab and for automatization

e.g

#!/bin/bash

mem=$(free -m | awk '/Mem:/{print $4}')

(( mem <= 500 )) && reboot

Make the script executable
chmod +x scriptname // note don't add an extension
Add the script to the cron
crontab -e

* * * * * user_to_run_the_script /path/to/the/script