But with all the reliability features coded into Google's software, the only reason the engineers knew it ever happened was when the cluster got slower and network traffic in the "cell" spiked as the system was balancing itself back to its original state.

Pike said he doesn't believe Google could have achieved this level of reliability with Windows.

"It was a good decision [to choose Linux] because it made it so flexible in the way you can do it," he said.

"We administer a massive cluster with remarkably few people. It would have been too hard to do what we did without open source."

Pike then jokingly said if Microsoft's claims about the number of Windows administrators required per server were true compared to Linux, "Google would be a much bigger company".