* Over four billion Web pages, each an average of 10KB, all fully indexed.
* Up to 2,000 PCs in a cluster.
* Over 30 clusters.
* Sustained transfer rates of 2Gbps in a cluster.
* An expectation that two machines will fail every day in each of the larger clusters.
* No complete system failure since February 2000.
Do I really need to say more? We all know by now how huge Google is and well, I won't go onto a glorifying rant but rather point you to a very interesting article posted on ZDNet where Google's vice-president of engineering, Urs Hölzle, gave an insight to would-be Google employees into just what it takes to run an operation on such a scale, with such reliability.