Inside Facebook

Facebook announced on the company blog on Sunday that 10-15% of photos users have uploaded to the site were temporarily unavailable due to a hardware failure. Tonight, Facebook says all those photos have been successfully restored.

While 10-15% may not seem like a lot, remember that Facebook crossed 10 billion user photos stored late last year and is the most popular photo sharing service on the web. Facebook says users are uploading about 850 million new photos each month, so the total number of photos on Facebook now could be over 14 billion. That means the number of photos missing was likely around 1-2 billion.

It’s one of the first larger-scale downtimes we’ve seen for Facebook Photos. Given that Facebook Photos is storing nearly a petabyte of data at this point and users are adding nearly a billion new photos to the system each month, the ops team seems to be doing a pretty great job.