> What law of physics necessitates that such an upgrade takes 6 hours?
the one where the customer isn't paying enough money to have somebody working 24/7?
If your business depends on a particular service, you don't accept something vague - you get things signed in contract with legally enforcible SLA's. If you can't afford that, then you just have to live with shitty service.
It's Google. You never see the Google front page go down. There's an implied availability that Google uses to their advantage. People are comfortable with upgrading _because_ it's Google. Google wouldn't fuck you.
the one where the customer isn't paying enough money to have somebody working 24/7?
If your business depends on a particular service, you don't accept something vague - you get things signed in contract with legally enforcible SLA's. If you can't afford that, then you just have to live with shitty service.