"If we had one data center serving the whole world there wouldn't be enough capacity. This distributed nature works well."

Google is tight-lipped about the exact number of servers it is running, but with the last count some years ago being 10,000, there's speculation now that the number could be hundreds of thousands.

However, Pike did say that nowadays Google's servers are custom-designed and run Red Hat Linux with a modified kernel.

"Failures happen no matter what you do, but if you plan for it you can survive," he said.

Pike reminisced about one such failure when a rack of GFS servers with about 50 machines and 10TB of disk and human error accidentally caused the whole rack to reset, wiping the disks clean.