I would like to know just how much disk space I will need for such a world in Minecraft. It will be stored on USB which has 3.12 GB of free storage remaining. This is for a Minecraft server. This world would be the size of normal Minecraft excluding the non-existent Far Lands.
Are you trying to build the Earth (it's actually about 22584607 by 22584607 metres surface area, about 3.2 times what you're asking about)? Well, the block height can take 256 values and each block uses at most ~2.5 bytes, so it's 12550824*12550824*256*2.5 = 100,814,837,170,544,640 bytes, aka 100,815,000 GB, aka 101 petabytes. You're going to need a bigger disk ;)
Compression could reduce this somewhat, but depends heavily on the complexity of the world. So unless your world is ultraflat it's probably still going to be a petabyte or more.
As the existing answers only guess about compression, I estimated the space requirements from an existing server. That server has a 60kx60k world (-30000 to +30000 each X and Z), which is approximately 50% generated, and which needs 28 GB.
Let's assume it needs 56 GB fully generated.
Your world has ~ 210 times the size in X AND Z, so 44,100 times the size. 44,100 * 56 GB makes 24,696,000, so a bit less than 25,000 TB, or 25 PB.
This is way more than achievable with a standard PC, but if you build a supercomputer, it's very well reachable. The IBM Summit has ten times as much, and it's a real bargain at $200M.
Now, let's check how much time you need to generate the world. On my Ryzen 7 3800X, using WorldBorder, I can generate approx. 200 chunks per second. Your world has (12550284²)/(16²) ~ 6.1*10¹¹ chunks. This makes 30 trillion seconds, or 35,606 days. Wow, just 100 years to populate your world after you've assembled the computer to store the data, and started the generation process.
Of course, you'll probably have more than one CPU in your supercomputer. Let's assume you have 64 cores, set up 64 instances of Minecraft, and let each of them generate a part of the world. Assuming the CPUs are faster than mine, this may give you a factor of 100. So your world may actually be done in just 1 year!
In regards to the main question of "How many bytes would a world of this size require?"
The answer to that varies between Minecraft version, the kind of compression involved and the specifics of the world being created, and thus is impossible to get anything more than a ballpark figure for.
In regards to the secondary question of "Can I fit a world of this size in the 3GB left over on my USB stick", I'd like to demonstrate a different way of proving that 3GB is nowhere near enough using a worked example and some fictitious assumptions to make the maths a bit more appealing.
Let's assume that:
- 1 chunk = 16x16x256 blocks
- 1 chunk requires 1 byte
- It's probably a lot more, this is a simplification
In which case the question becomes how many bytes would you need to store a
12550824 * 12550824 world...
12550824 / 16is
- The number of chunks along each dimension
784426.5 * 784426.5is
- The number of total chunks, and thus the number of bytes needed to store that many chunks, assuming 1 byte per chunk
615324933902.25 / 1024is
600903255.763916015625 / 1024is
586819.5857069492340087890625 / 1024is
- The total number of terabytes, stopping there because that's smaller than 1 petabyte
~574 Terabytes worth of fictional 1-byte chunks.
So assuming that 1 chunk could magically be stored in a single byte (a feat that is, as far as I'm aware, impossible), you're already looking at terabytes of information. In reality, chunks would undoubtedly require more than just a single byte of information, so you'd easily be looking at more than just a few terabytes..
Hence the answer is "Not even close". Either shrink your world or get a bigger USB stick.
As other answers have stated, a fully generated 12550824 x 12550824 world can take up to 12550824 x 12550824 x 256 x 2.5 bytes = 1.00815e+17 bytes or 101 PB. If we want to be generous and assume that large chunks of air blocks are not stored, we can probably reduce the effective height to 128 blocks, yielding 50.5 petabytes. However, your world will only take up this much space if every single chunk within that space has been observed by a player.
If, instead of doing that, you spawn at (0, 0) and immediately teleport to (12550824, 12550824) (
/tp 12550824 ~ 12550824), you will instead only generate the chunks immediately around (0, 0) and (12550824, 12550824). If your render distance is 32 chunks, this means approximately 32 x 32 x 2 = 2048 chunks will be generated. This yields a total of 134,217,728 blocks, for up to 335,544,320 bytes, or 335 MB - well within the confines of your USB drive. None of the other chunks, either between the two teleport points or anywhere else in those square confines, exist - you've never seen them, so why should the engine go through the trouble of generating them?
Now let's consider a case where instead of teleporting, you simply walk due East until you reach (12550824, 0). This will essentially generate a straight line of chunks around you, reaching up to 32 chunks (or 1024 blocks) on either side of the line, plus 1024 blocks behind your start point and 1024 blocks ahead of your finish point. This means that a rectangular prism of (12550824 + 2048) x 2048 x 256 = 6,581,320,155,136 blocks will be generated, or up to 16,453,300,387,840 bytes or 16.5 TB. Still way too big for your USB stick, but a small amount of compression would probably get that under 16 TB, and you can buy good-quality 16 TB hard drives for less than $500 USD.
As a middle ground, let's consider teleporting through non-command methods - using Nether portals. Each block length down in the Nether is equivalent to 8 lengths in the Overworld, so if you build a Nether portal at (0, 0), walk due East to (1568853, 0), and build another Nether portal there, you will pop out at (12550824, 0) in the Overworld. The Nether will generate a rectangle of chunks as in the previous paragraph, though this rectangle will be eight times smaller: (1568853 + 2048) x 2048 x 256 = 823,604,543,488 blocks, or 2.06 TB. In the Overworld, however, the space between the two portals will not be generated, and you will end up with the two islands of chunks described in the
/tp case - only 335 MB, which keeps the effective total data to 2.06 TB. A little compression will get that under 2 TB, and 2 TB drives are even more affordable, with good quality drives coming in at just a little more than $50 USD.
Alright, so... you have 1255084 x 1255084 blocks x 256 (remaining air blocks or other block u wanna put) and multiply. you get 4.0326038e+15. assuming each block is a byte, you have 4.0326038e+15 bytes, which is a LOT more than 3 GB. so you may want to consider a smaller world. The best USB sticks sold right now for that amount of data are hundreds of USD.