Create a huge file in less than a second
Here’s how to create a large file in Linux:
dd if=/dev/zero of=filename bs=1 count=1 seek=$((100*1024*1024*1024))
This creates what is called a “sparse file”. However,
df will not recognize the reduction in size. From what I can tell, there is no way to get
df to recognize sparse files.
df will always disagree.