.\" -*- nroff -*-
.\" Copyright 2009 by Karel Zak.  All Rights Reserved.
.\" This file may be copied under the terms of the GNU Public License.
.\"
.TH WIPEFS 8 "October 2009" "util-linux" "System Administration"
.SH NAME
wipefs \- wipe a signature from a device
.SH SYNOPSIS
.B wipefs
.RB [ \-ahnptV ]
.RB [ \-o
.IR offset ]
.I device...
.SH DESCRIPTION
.B wipefs
can erase filesystem, raid or partition table signatures (magic strings) from
the specified
.I device
to make the signature invisible for libblkid.

.B wipefs
does not erase the filesystem itself nor any other data from the device.
When used without options \fB-a\fR or \fB-o\fR, it lists all visible filesystems
and the offsets of their basic signatures.

Note that some filesystems or some partition tables store more magic strings on
the devices. The
.B wipefs
lists the first offset where a magic string has been detected. The device is
not scanned for additional magic strings for the same filesystem. It's possible
that after \fBwipefs -o <offset>\fR will be the same filesystem or partition
table visible by another magic string on another offset.

When used with option \fB-a\fR then all for libblkid visible magic strings are
erased.

.SH OPTIONS
.IP "\fB\-a, \-\-all\fP"
Erase all available signatures. This set of erased signatures could be
restricted by \fB\-t <list>\fP option.
.IP "\fB\-h, \-\-help\fP"
Print help and exit.
.IP "\fB\-n, \-\-no\-act\fP"
Causes everything to be done except for the write() call.
.IP "\fB\-o, \-\-offset\fP \fIoffset\fP
Specify the location (in bytes) of the signature which should be erased from the
device.  The \fIoffset\fR number may include a "0x" prefix; then the number will be
interpreted as a hex value.  It is possible to specify multiple \fB-o\fR options.

The \fIoffset\fR argument may be followed by the multiplicative
suffixes KiB=1024, MiB=1024*1024, and so on for GiB, TiB, PiB, EiB, ZiB and YiB
(the "iB" is optional, e.g. "K" has the same meaning as "KiB") or the suffixes
KB=1000, MB=1000*1000, and so on for GB, PB, EB, ZB and YB.
.IP "\fB\-p, \-\-parsable\fP"
Print out in parsable instead of printable format.  Encode all potentially unsafe
characters of a string to the corresponding hex value prefixed by '\\x'.
.IP "\fB\-q, \-\-quiet\fP"
Suppress output messages after successful signature wipe.
.IP "\fB\-t, \-\-types\fP \fIlist\fP
Used to limit the set of printed or erased signatures. More than one type may
be specified in a comma-separated list.  The list of types or individual types
can be prefixed with 'no' to specify the types on which no action should be
taken. For more details see mount(8).
.IP "\fB\-V, \-\-version\fP"
Output version information and exit.
.SH AUTHOR
Karel Zak <kzak@redhat.com>.
.SH AVAILABILITY
The wipefs command is part of the util-linux package and is available from
ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
.SH SEE ALSO
.BR blkid (8)
.BR findfs (8)