To run script or any command really at a regular interval
Here are a few programs that might help you
is a wonderful resource for software of all types.
If you want to mirror your drive you might want to check out
software raid 1
This will provide an instantaneous and complete backup of the
entire system in case of catastrophic failure. Although it does
require a lot of space. And should be done on a completely
different physical harddrive instead of just a different partition.