Quickly create large files for testing

[I_D]

Hope you guys don't mind me posting a guide I found -> here

Sometimes you need a large file fast to test data transfers or disk performance.
Windows includes a utility that allows you to quickly generate a file of any size instantly.
Open an administrative level command prompt.

Run the following command:

fsutil file createnew <file> <size in bytes>

For example, this command will create a 1GB file called 1gb.test on my desktop:

fsutil file createnew c:\users\steve\desktop\1gb.test 1073741824

The key is to input the size of the file in bytes so here are some common file sizes to save you from math:

1 MB = 1048576 bytes

100 MB = 104857600 bytes

1 GB = 1073741824 bytes

10 GB = 10737418240 bytes

100 GB =107374182400 bytes

1 TB = 1099511627776 bytes

10 TB =10995116277760 bytes

source

 

[jfeldt]

Nice, thanks! In the past, I've always resorted to using dd on a unix system then transferring the files to a Windows system, this saves some time for cases when you don't care what the file is composed of.

 

[Stereodude]

But do you end up with an incompressible file or a compressible one?

 

[Deslok]

But do you end up with an incompressible file or a compressible one?

fsutil creates empty files so they're compressible

 

[jfeldt]

Since a 1GB file is created essentially instantly, I figured it was empty, and when I use default 7-zip parameters, a 1GB file zips down to ~1.1MB, so yep.

 

[Deslok]

3 Ways to Create Random Dummy Files in Windows, with a Given Size | Digital Citizen

I've used the second one before