How do social media companies like twitter or youtube not run out of space for posts?
I know memory is fairly cheap but e.g. there are millions of new videos on youtube everyday, each probably few hundred MBs to few GBs. It all has to take enormous amount of space. Not to mention backups.
Google just has a lot of storage space. They have dozens of data centers, each of which is an entire building dedicated to nothing but storing servers, and they’re constantly adding more servers to previous data centers and building new data centers to fit even more servers into once the ones they have are full.
IIRC, estimates tend to put Google’s current storage capacity somewhere around 10-15 exabytes. Each exabyte is a million terabytes. Each terabyte is a thousand gigabytes. That’s 10-15 billion gigabytes. And they can add storage faster than storage is used up, because they turn massive profits that they can use to pay employees to do nothing but add servers to their data centers.
Google is just a massive force in terms of storage. They probably have more storage than any other organization on the planet. And so, they can share a lot of it for free, because they’re still always turning a profit.
There are also techniques where data centers do offline storage by writing out to a high volume storage medium (I heard blueray as an example, especially because it's cheap) and storing it in racks. All automated of course. This let's them store huge quantities of infrequently accessed data (most of it) in a more efficient way. Not everything has to be online and ready to go, as long as it's capable of being made available on demand.
That's the difference between getting a video served off a disk off in some random DC in some random state vs. the videos being served off a cache that lives at your ISP.
It's not offline storage vs. disk, it's a special edge-of-network cache vs. a video that doesn't live in that cache, but is still on a hard drive.
This is an article from 2015 where Facebook/Meta was exploring Blu-ray for their DCs. You're definitely right though. Tape is key as the longest term storage.
Super cool, blew my mind! I would love to see it in operation. The logistics from the machine side + the storage heuristics for when to store to a disc that's write-only sounds like a really cool problem.
I think that was just an example. Tiered storage is fairly common, though. NVMe SSDs are faster than SATA SSDs, which are way faster than hard drives. Amazon has a “glacier” tier of cloud storage which is pretty cheap, but it can take time (hours) or money to download your data. Great for backups though.
And thats just Google. Amazon and Microsoft also run also have massive massive data capacity that runs large chunks of the internet. And then you get into the small and medium sized hosting companies, that can be pretty significant on their own.
15 exabytes sounds low. Rough math, 1 20 TB hard drive per physical machine with 50,000 physical machines is one exabyte raw storage. I bet 50,000 physical machines is a small datacenter for Google.