[jsty]

However much we technical people might salivate at the prospect of designing a multi-cloud solution, for the vast majority of businesses it simply isn't worth the cost / complexity. I'd wager 90-something percent of applications could suffer multi-hour outages without impacting business function to any measurable degree.

Plus the fact that without serious investment, you're probably more liable to decrease availability by going multi-cloud thanks to the increased system complexity.

[hinkley]

The real trick here, which many people don’t want to look at, is to avoid overly centralizing your workflow.

I can get a lot of work done while Outlook is down. Hell, probably more work done.

If our build server is down I can work for a couple hours (unless we’ve done something very bad). Same for git or our bug database or wiki or or or. When I get stuck on one thing I can swap to something else every couple of hours. And there is always documentation (writing or consuming).

But if some idiot, hypothetically speaking of course, puts most of these services into the same SAN, then we are truly and utterly screwed if there is a hardware failure.

Similarly if you make one giant app that handles your whole business, if that app goes down and there are no manual backups you might as well send everybody home.

I went to get a drink the other day and the place looked funny. They’d tripped a circuit breaker and the whole kitchen lost power. But the registers and the beverage machines were on a separate circuit. And since they sold drinks and food in that order, they stayed open and just apologized a lot. Whoever wired that place knew what they were doing.

[hunter2_]

Probably lost 1 of 3 phases. You're quite right in that the decision of what phase a circuit is on has a lot to do with business, and hopefully no major repurposing of the space without rewiring the space has occurred. For lighting, you'd want 1/3 of fixtures per room to go out, not 1/3 of your rooms in their entirety. For appliances and receptacles, you'd rather lose a whole function (the kitchen) than be able to cook but not do dishes, with every function trying to figure out oddball workarounds.