wipe-free(1) wipe-free(1)
NAME
wipe-free - overwrite all free space in a filesystem with zeros
SYNOPSIS
wipe-free [-b block_size] [-c count] [-m max_chunks] [-h(elp)]
DESCRIPTION
wipe-free writes very large files containing all zeros to the current
directory until the filesystem is filled (or the specified maximum num-
ber of files is written, and then deletes them all. This effectively
zeros out all free space in the filesystem, making the filesystem much
more compressible when backing up entire filesystem images. The dd,
filesize, sync, and tempname utilities serve as the engines of the
wipe-free utility.
OPTIONS
-b BLOCK_SIZE
Set the block size used by dd, in bytes. The default value is
4096.
-c COUNT
Set the number of block per zero file. The default value is
262144, which is enough to yield a file of exactly 1 GiB.
-m MAX_CHUNKS
Limit the number of files written by wipe-free. The default
value is 4096, which is enough to fill a 4 TiB drive using the
defaults given above. -h Print help and quit.
NOTES
The reason that wipe-free writes zeros in chunks (instead of all at
once), is that several filesystems tends to slow down markedly as they
approach full. NTFS is one such culprit. With the periodic listing of
the zero files, the user can detect such slowdown and manually halt
wipe-free (via Ctrl-C) if desired.
Additionally, it should be noted that wipe-free is NOT a secure wiping
utility. If you're trying to ensure that data potentially stored in
unused sectors cannot ever be read, then a formal secure erase program
(such as shred or a utility from the secure_deletion package) should be
used instead.
Alternatives to wipe-free include zerofree (which works on ext2/3/4
filesystems) and the three-step sequence of ntfsclone --save-image, dd
if=/dev/zero, and ntfsclone --restore-image (which works on NTFS
filesystems). These alternatives are more thorough than wipe-free, but
are limited to specific filesystems.
SEE ALSO
dd(1), filesize(1), shred(1), sync(1), tempname(1), ntfsclone(1),
zerofree(1)
COPYRIGHT
Copyright (C) 2011-2020 by Brian Lindholm. This program is free soft-
ware; you can use it, redistribute it, and/or modify it under the terms
of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MER-
CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.
littleutils 2020 Oct 19 wipe-free(1)
littleutils 1.2.3 - Generated Tue Dec 1 07:59:35 CST 2020