One thing not everyone knows about Facebook is they’re also the biggest photo storage and sharing site on the web. To date, Facebook users have uploaded over 6.5 billion images. Facebook stores them in 5 sizes each, totaling over 30 billion files that take up about 540 TB of disk space.
Recently, Jason Sobel, Facebook’s manager of infrastructure engineering, gave a presentation at the Stanford ACM entitled Needle in a Haystack: Efficient Storage of Billions of Photos. He talks about the infrastructure Facebook has built to handle this volume of data and serve it at high performance (Facebook serves almost half a million images per/second at peak load). You can check out the presentation here.