Zerofree is a utility which scans the free blocks in an ext2/3/4
filesystem and fills any non-zero blocks with zeroes.
This is useful if you have an ext2/3/4 virtual disk image
(e.g. VirtualBox' .vdi) that you wish to compact.
See project homepage for information and usage.
Maintained by: B. Watson
(the SlackBuild does not include the source)