[NikolaNovak]

We've run 375,000 self-service employees ERP system (so much heavier single transaction than HN) on a single (large:) db2/aix box with no downtime over last 8 years. That's well within published specs for that hardware / software combo.

Yes we do have a DR box in another data centre now, in case of meteorite or fire.

This used to be the norm. A single hardware / software box CAN be engineered for high uptime. It's perfectly fine when we choose to go the other way and distribute software over number of cheap boxes with meh software, but I get pet-peeved when people assume that's the ONLY way :).

[midasuni]

I’m paranoid about environmental situations so always have a failover, but then my DR plans include events such as “Thames barrier fails”.