The zeroer utility can be used to wipe empty space on a disk. In contrary to dd, zeroer does not wipe existing files on a partition. It overwrites the unallocated disk space around existing files, which means that deleted files cannot be restored after processing a certain partition with zeroer. The utility's principle consists in writing huge zero-padded memory blocks to a file. To a certain extent this works similar to dd, however zeroer dynamically reduces the blockwriter's buffer size when the filesystem is going to be full. WWW: http://critical.ch/zeroer/