backup strategy questions

Greetings Everyone,

I have been using psync to back up my entire disk (about 20GB) to a  
local hard drive (300GB).  Previously, I had been updating the backup  
drive with changes, but I was concerned that all history was  
unrecoverable.
So I wrote a little program that creates a new directory each time  
(ie, 2005-08-09) and does a full backup using psync to the directory.
My question:  In the event of a hard disk failure, will I be able to  
boot from a full copy in a directory?   How would I be able to recover?
Joe.