A small but useful shell script to send an alert email to one or more system administrator(s), if server memory is running low.
This script is particularly useful for keeping an eye on Linux VPS (Virtual Private Servers) with small amount of memory
First it checks the free memory size, then determines if amount of free memory is less or equal to a specified size (100 MB for the purpose of this guide), used as a bench mark for the least acceptable free memory size. If this condition is true, it will send an alert email to specified email addresses.