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.
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 Blu-ray 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.
Edit: Clarifying that tape medium is typically used for the longest term storage with the caveat that read is slow, so that used for the stuff that is least likely to be accessed. For things that are accessed infrequently but still need to be available relatively frequently you can have a “caching layer” which is what I was referring to with the discs. It’s a tradeoff between speed of access and information density. Here’s an article from 2015 where Facebook/Meta is discussing their design: https://engineering.fb.com/2015/05/04/core-data/under-the-hood-facebook-s-cold-storage-system/
You can feel it on YouTube when you try to access an old video that no one has watched in a long time.
every time it lags, it’s because youtube has to send someone down to the basement to retrieve the correct blu-ray disc from a storage room
God bless those interns. Earning those college credits.