Mac OS X: create arbitrarily large sparse/dummy file

On Mac OS X, you can use command dd or mkfile to create an arbitrarily large dummy file. The following examples create a 20GB file:

• dd (works on Mac OS/Linux/Solaris/Unix...)

  dd if=/dev/urandom of=sparseFile bs=1m count=2000000

• mkfile (works on Mac OS/Solaris/Irix)

  mkfile 20g sparseFile

See also

• dd man page
• mkfile man page
• http://unix.stackexchange.com/questions/38292/creating-an-arbitrarily-large-fake-file