Facebook logo Email or Phone Password Keep me logged in Forgot your password? Sign Up By Peter Vajgel on Thursday, April 30, 2009 at 2:27pm The Photos application is one of Facebook’s most popular features. Up to date, users have uploaded over 15 billion photos which makes Facebook the biggest photo sharing website. For each uploaded photo, Facebook generates and stores four images of different sizes, which translates to a total of 60 billion images and 1.5PB of storage. The current growth rate is 220 million new photos per week, which translates to 25TB of additional storage consumed weekly. At the peak there are 550,000 images served per second. These numbers pose a significant challenge for the Facebook photo storage infrastructure. The old photo infrastructure consisted of several tiers: Upload tier receives users’ photo uploads, scales the original images and saves them on the NFS...