Thanks for the great explanation. I agree that a Chaos Monkey test something a lot more easier to recover from than a whole datacenter getting down.

I remember having read somewhere about some company (Facebook/Google/Amazon/Twitter/Dropbox or something at the same scale) that regularly simulates a whole datacenter failure, which made believe it is possible to automatically recover from this.

Are you saying that even the companies I mentioned have the same issues as OVH when they recover from a complete power failure?