Sparse Files — Commands Overview

I was just checking which commands are supporting sparse files. I post hereafter a short overview of what I found out (working on Linux).

• Create a sparse file of 20 GiB:
  dd if=/dev/zero of=foo bs=1 count=1 seek=20G
• Check that a file is sparse:
  ls -alsh
  Compare the first versus second size column (the first one is the space taken on disk).
• Copy a sparse file:
  cp foo bar
  Copy already detects and handles correctly sparse files.
• Make a non-sparse file sparse (works only if it contains blocks filled with zeros):
  cp --sparse=always foo bar
• Expand a sparse file to a non-sparse one:
  cp --sparse=never foo bar
• Copy remotely a sparse file: scp does not support sparse files, it will expand them to non-sparse ones. Rsync does support them. Just use the -S or --sparse option. Example:
  rsync -vS foo root@someserver:/some/path/