zerofill Files

Project: zerofill

Fills unused space in a file system with 0-bytes and overwrites unused inodes.

The sole purpose of this program is to overwrite remains of deleted data
with zero-bytes only; no extra-secure-deletion aspects considered.
In my case this is used to prepare a virtual disk image for compression
at higher efficiency for backups using an ordinary stream compressor ala
xz/pxz/gzip/pigz/lzop or similar, creating a simple backup of an entire
vdisk incl. MBR, bootloader, partition table, file systems and everything.

This program should be run as root user, otherwise it might not be able to
work properly due to user access/privilege restrictions.

Also, the target file system should not be in use other than just being
mounted because it will be filled up to the very last sector which could
cause problems with certain mount points, such as "/var" if other processes
try to write data at the same time, so for system partitions i would
suggest to mount the partition from a second (rescue-/backup-) system.

For more secure methods to erase traces of deleted files, please refer to
projects like secure-delete <http://www.thc.org>
or scrub <http://code.google.com/p/diskscrub/>

Code is based on the sfill sourcecode from the secure-delete project (v3.1)
originally written by van Hauser / [THC], vh@thc.org, <http://www.thc.org>.

Removed all secure/random/multi-pass functionality, fixed a few things
(incl. one major bug) and also removed all options - just zerofill, ma'am.

Author:      Oliver Lange<zerofill@bloody.in-berlin.de>

Project URL: http://zerofill.sourceforge.net

License:     GPL version 2