To Create a File with Specific Size

To create a file Test file with specified size 50Kb

dd if=/dev/zero of=Testfile bs=1024 count=50

Where,

dd - dd is a common UNIX program whose primary purpose is the low-level copying and conversion of raw data. dd is an abbreviation for "dataset definition"
if - Input File(The partition name in this case)
of - Output File(The name of the file to be created)
bs - Block Size(Default value is 512bytes)
count - the size of the file in KB

This is helpful when we require a test file with some minimum size to check the download speed or to check network performance.

Cheers
Nobs