In the world of social networks, the lifespan of data has been shortened to just a few moments. You upload your selfie, you enjoy the ‘likes’ for a couple of hours, and then you upload another one – pushing another batch of data into virtual oblivion. Have you ever wondered where your photos end up after their death? Yes – they go into a “cyber graveyard” or – if you will – a “cyber morgue”, that is; cold storage. The issue of cold storage concerns many companies that are serious about archiving data, but there are very few which have such huge and rapidly growing storage needs as Facebook.
Of course, the death of our party photos is only apparent – because when we upload them to the platform we expect them to be always accessible. And that’s what, for a long time, Facebook experts have been working on. They needed a data storage system which would meet three basic requirements:
- it needed to have immense storage capacity (the number of photos uploaded to the platform is huge and grows exponentially after each Saturday evening),
- it needed to be economical,
- but also it needed to allow for a quick, although not very frequent, access to the stored data (in case, at this very moment, you wanted to show off your year-old photos).
Open Compute Project, initiated by Facebook, created for this purpose a data archive (OCP Storage Vault), saved on hard disk drives (HDD) using a technique called Shingled Magnetic Recording, so called because of the technology whereby a part of a wide magnetic track is overlapped by another one, increasing the amount of writable area. In this way it minimises the loss of space. These kinds of disks are economical, efficient, and allow for relatively quick access to data – making them an ideal candidate for storing archived photos which are not going to be frequently accessed by the users.
How many photos can we upload to such and archive? Go forth and try and break it selfie takers!