updated: 03 Sep 2008

You can create a file with a given size using dd command.

$ cd tmp # use /tmp, wiki doesn't allow it
$ dd if=/dev/zero of=testfile bs=1M count=10

This will create a /tmp/testfile with size 10 MB. What this means:

• if - input file, in this case the special /dev/zero
• of - output file, in this case /tmp/testfile
• bs - block size (here 1 MByte)
• count - how many blocks (size bs)