centos man page for zerofill

zerofill(1)                                                        GNU Telephony                                                       zerofill(1)

NAME
       zerofill - clear unused disk space and blank devices.

SYNOPSIS
       zerofill [options] [devices] ...

DESCRIPTION
       This command is a relative of nullfile.  Like nullfile, it can be used to write all unused disk space with '0', thereby making file systems
       that are stored on virtual machines easier to pack.  In addition, zerofill can fill unused disk space  with  random  data  before  zeroing,
       which  can be useful to remove forensic trace of deleted files.  Finally, zerofile can be told to operate on and zero (erase) complete disk
       devices.

OPTIONS
       --random=count
              Number of passes to use writing random data before wiping data.

       --help Outputs help screen for the user.

AUTHOR
       zerofill was written by David Sugar <dyfet@gnutelephony.org>.

REPORTING BUGS
       Report bugs to bug-commoncpp@gnu.org.

COPYRIGHT
       Copyright (C) 2010 David Sugar, Tycho Softworks.
       This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICU-
       LAR PURPOSE.

GNU uCommon                                                        January 2010                                                        zerofill(1)