I think most of the OS backup tool are not FOSS compliant and definitely NOT FREE. Let's face the facts... we aren't all rich people or rich companies or organizations and the economy is bad. Who wants to buy those expensive and commercial OS backup tool like Acronis ...etc.
So some would suggest just totally forget about backup and wish for all sorts of good luck that their machines don't crash ? Ok, maybe it could work... but sometimes things just go crashing ?
Many of those free and open source OS backup tools are either incomplete , alphas , betas , not tested , not ready , shitty , command line /prompt / console / terminal , highly complicated , alien languaged ... bad GUI ...
I think it's time someone out there make a good and totally usable , free , open source , GNU FOSS approved OS backup tool to backup Windows and POSIX / UNIX systems.
Someone must really take a first step out and play 'Robin Hood' just to get the ball rolling first.