How do those free cloud service store data?

[brannsiu]

Google drive, even if it only provides 15GB for free users, but there could be countless free users, while some services in China like Baidu cloud, free users
could get a permanent 2TB cloud storage if they install their mobile apps and login for at least one time.

How do those cloud services store such a large amount of data?
Do they use physical hard drives like what we .. citizens, consumers buy in the market? Or do they have any special strategy to store that large amount of data??

 

[2sidedpolygon]

Just lots of storage. Probably using some fast SSDs that they bought in bulk.

 

[punkncat]

Without getting too specific, they have data centers with row upon row of "computers and storage".

In essence, for an agreement to use their service in which they spy on you and sell your usage data off to partners, they "give" you an amount of space that is in itself insignificant. They know that if you really use it and start needing it that you will very quickly outpace the "free" space so that in addition to the rest mentioned above, you have to start paying for monthly storage space. They also know that typically you won't go clean those files out due to the sheer time, so the longer you use them, the more space you will eventually need, increasing billing.

 

[kanewolf]

Yes, they use SATA hard drives. 4 to 10TB / drive. Many of cloud providers build a standard config, which may have 20 drives associated with a physical chassis. They may sell the CPU cycles but not have demand for the storage. So they "give away" the resource with some intangible cost (e-mail address, phone #, etc).

 

[cryoburner]

Keep in mind that 15GB of hard drive storage is dirt cheap. It's possible to buy a 4TB hard drive and have it shipped to your door for $100. A single 4TB drive could hold more than 250 15GB blocks of data, which would work out to under 40 cents worth of storage per user. Of course, they undoubtedly have backups of the data stored on multiple drives, as well the same data mirrored in various locations to avoid outages, so more storage than that would undoubtedly be used. And of course there are going to be additional costs associated with running the servers. However, most people are also not going to fill their storage to anywhere near capacity, meaning significantly more accounts can be stored per drive. Assuming they make money through ads, as well as from a portion of their users subscribing to premium accounts for access to more storage (again, most of which will not be in use), they should be able to turn a profit.