Unix asked where Google stores all those hard disks it uses to store all the internet's data.

I did some research and some math. If you want to skip all the calculations I did, here's the bottom line:

1. I figure that Google spent a little over $9 Billion for new hard disks to store all the data that the internet generated in 2017. Google can easily afford that.

2. I figure that Google had to buy a building the size of one of the largest hotels in the world to house all those new hard disks (or a bunch of smaller buildings that add up to the same number of square feet). But that building - even at about $2 Billion - costs a lot less than the hard disks, so Google can afford that too.

Now for the research (links to web sites) and details (calculations). We need some numbers.

How many dollars per TB does hard disk storage cost?

The cheapest option [dollars per TB] on the web page linked below is an external 8TB external hard disk for $160.

Fry's Electronics Prices for External Seagate DrivesThat works out to $20 per TB -- retail price.

Wholesale is probably about $10 per TB. Google may buy storage cheaper than that, but probably not much cheaper.

So multiply the internet's daily data production by $10 for every TB to calculate Google's daily expense for new hard disks (assuming Google retains 100% of all new internet data -- a dubious assumption).

Now, how many Tera-Bytes are generated on the internet each day?

I did a little searching. One web site says that, in 2017, 2.5 quintillion bytes per day were created.

https://www.iflscience.com/technology/how-much-data-does-the-world-generate-every-minute/That means that the internet generated 2,500,000 Terabytes per day. How do I know that?

Let's detour into the names of large numbers.

Note that I'm using powers of 10 instead of powers of 2 in order to keep the math easy.

One Million is 10 to the sixth power = 10^6 = 1 Megabyte

One Billion is 10 to the ninth power = 10^9 = 1 Gigabyte

One Trillion is 10 to the 12th power = 10^12 = 1 Terabyte

One Quintillion is 10 to the 18th power = 10^18 = 1 Exabyte = 1 Million Terabytes

Returning to the internet's data production, 2.5 quintillion bytes per day = 2,500,000 Terabytes per day.

Multiply by $10 per Terabyte to get $25,000,000 dollars per day to buy hard disks for all the new data in 2017.

Then multiply by 365 days per year to get $9,125,000,000 dollars per year.

Conclusion:

Google can easily afford to buy all the hard disks it needs to store all internet data production.

HOWEVER, we're not quite done yet. Unix asked where all those hard disks are stored.

Well, my Seagate backup drive enclosure (sitting on my desk) is 8 inches X 5 inches X 1.5 inches.

Google mounts all its drives on racks, and space between the drives is needed for cooling air flow.

And all the wires take up a significant amount of space too.

I'll assume 10 X 7 X 3 inches of space per drive.

Now let's assume each rack has four stacks and each stack is 20 drives.

The height of the rack would be 20 drives X 3 inches per drive = 60 inches = 5 feet.

The width would be 7 inches X 2 stacks = 14 inches

The length would be 10 inches X 2 stacks = 20 inches.

Overall rack dimensions: 60 inches tall X 14 inches wide X 20 inches long.

Since people need to walk among the racks, we need 2 feet = 24 inches between rows of racks.

Let's assume that each row is 36 racks long = 36 X 14 = 504 inches = 42 feet

Let's assume 9 rows = (20 + 24) X 9 = 396 inches = 33 feet.

Total area = 42 feet X 33 feet = 1386 square feet for one room with 9 rows of racks.

Total number of drives in that room = 80 drives per rack X 36 racks per row X 9 rows = 25,920 drives.

Let's make the math easy and assume 10 TB per drive, giving us 259,200 TB.

10 rooms would give us 2,592,000 TB -- more than enough for one day's internet data. And 3600 rooms would give us more than enough to store a full year's internet data. Three hotels in Las Vegas have more rooms than that, according to this web page.

https://en.wikipedia.org/wiki/List_of_largest_hotelsBottom Line:

Google has to buy a building the size of one of the largest hotels in the world to house all the new hard disks it buys every year (or a bunch of smaller buildings that add up to the same number of square feet). But that building - even at about $2 Billion - costs a lot less than the hard disks, so Google can afford that too.