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1 | .\" Copyright 2009 by Karel Zak. All Rights Reserved. |
2 | .\" This file may be copied under the terms of the GNU Public License. | |
3 | .\" | |
92f1c5ab | 4 | .TH WIPEFS 8 "December 2014" "util-linux" "System Administration" |
c49057d2 | 5 | .SH NAME |
f126cd46 | 6 | wipefs \- wipe a signature from a device |
c49057d2 KZ |
7 | .SH SYNOPSIS |
8 | .B wipefs | |
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9 | .RB [ options ] |
10 | .IR device ... | |
11 | .sp | |
12 | .B wipefs | |
13 | .RB [ \-\-backup ] | |
14 | .RB \-o | |
15 | .IR offset | |
16 | .IR device ... | |
17 | .sp | |
18 | .B wipefs | |
19 | .RB [ \-\-backup ] | |
20 | .RB \-a | |
1faf44f0 | 21 | .IR device ... |
c49057d2 KZ |
22 | .SH DESCRIPTION |
23 | .B wipefs | |
1faf44f0 | 24 | can erase filesystem, raid or partition-table signatures (magic strings) from |
f126cd46 | 25 | the specified |
c49057d2 | 26 | .I device |
1faf44f0 | 27 | to make the signatures invisible for libblkid. |
c49057d2 | 28 | .B wipefs |
0791a058 | 29 | does not erase the filesystem itself nor any other data from the device. |
92296e9b | 30 | |
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31 | When used without any options, wipefs lists all visible filesystems and the |
32 | offsets of their basic signatures. The default output is subject to change. | |
33 | So whenever possible, you should avoid using default outputs in your scripts. | |
34 | Always explicitly define expected columns by using | |
35 | .B \-\-output | |
36 | .I columns-list | |
37 | in environments where a stable output is required. | |
f126cd46 | 38 | |
081dc33b | 39 | .B wipefs |
92f1c5ab BS |
40 | calls the BLKRRPART ioctl when it has erased a partition-table signature |
41 | to inform the kernel about the change. | |
081dc33b | 42 | |
92f1c5ab | 43 | Note that some filesystems and some partition tables store more magic strings on |
92296e9b | 44 | the device (e.g. FAT, ZFS, GPT). The |
f126cd46 | 45 | .B wipefs |
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46 | command (since v2.31) lists all the offset where a magic strings have been |
47 | detected. | |
f126cd46 | 48 | |
92f1c5ab | 49 | When option \fB-a\fR is used, all magic strings that are visible for libblkid are |
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50 | erased. In this case the |
51 | .B wipefs | |
52 | scans the device again after each modification (erase) until no magic string is found. | |
f126cd46 | 53 | |
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54 | Note that by default |
55 | .B wipefs | |
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56 | does not erase nested partition tables on non-whole disk devices. |
57 | For this the option \fB\-\-force\fR is required. | |
24ed0781 | 58 | |
c49057d2 | 59 | .SH OPTIONS |
1faf44f0 BS |
60 | .TP |
61 | .BR \-a , " \-\-all" | |
62 | Erase all available signatures. The set of erased signatures can be | |
92f1c5ab | 63 | restricted with the \fB\-t\fR option. |
1faf44f0 | 64 | .TP |
7e658c15 OO |
65 | .BR \-b , " \-\-backup" |
66 | Create a signature backup to the file $HOME/wipefs-<devname>-<offset>.bak. | |
92f1c5ab | 67 | For more details see the \fBEXAMPLES\fR section. |
7e658c15 | 68 | .TP |
1faf44f0 | 69 | .BR \-f , " \-\-force" |
2968c3fc | 70 | Force erasure, even if the filesystem is mounted. This is required in |
92f1c5ab | 71 | order to erase a partition-table signature on a block device. |
1faf44f0 BS |
72 | .TP |
73 | .BR \-h , " \-\-help" | |
b4362b6f | 74 | Display help text and exit. |
1faf44f0 | 75 | .TP |
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76 | .BR \-J , " \-\-json" |
77 | Use JSON output format. | |
78 | .TP | |
79 | .BR \-n , " \-\-noheadings" | |
80 | Do not print a header line. | |
81 | .TP | |
82 | .BR \-O , " \-\-output " \fIlist\fP | |
83 | Specify which output columns to print. Use \-\-help to | |
84 | get a list of all supported columns. | |
85 | .TP | |
1faf44f0 | 86 | .BR -n , " \-\-no\-act" |
c49057d2 | 87 | Causes everything to be done except for the write() call. |
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88 | .TP |
89 | .BR \-o , " \-\-offset " \fIoffset\fP | |
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90 | Specify the location (in bytes) of the signature which should be erased from the |
91 | device. The \fIoffset\fR number may include a "0x" prefix; then the number will be | |
92 | interpreted as a hex value. It is possible to specify multiple \fB-o\fR options. | |
92f1c5ab | 93 | .sp |
d636d6d8 | 94 | The \fIoffset\fR argument may be followed by the multiplicative |
1faf44f0 BS |
95 | suffixes KiB (=1024), MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB |
96 | (the "iB" is optional, e.g. "K" has the same meaning as "KiB"), or the suffixes | |
97 | KB (=1000), MB (=1000*1000), and so on for GB, TB, PB, EB, ZB and YB. | |
98 | .TP | |
99 | .BR \-p , " \-\-parsable" | |
11295cd1 | 100 | Print out in parsable instead of printable format. Encode all potentially unsafe |
c49057d2 | 101 | characters of a string to the corresponding hex value prefixed by '\\x'. |
1faf44f0 BS |
102 | .TP |
103 | .BR \-q , " \-\-quiet" | |
92f1c5ab | 104 | Suppress any messages after a successful signature wipe. |
1faf44f0 BS |
105 | .TP |
106 | .BR \-t , " \-\-types " \fIlist\fP | |
107 | Limit the set of printed or erased signatures. More than one type may | |
108 | be specified in a comma-separated list. The list or individual types | |
f126cd46 | 109 | can be prefixed with 'no' to specify the types on which no action should be |
1faf44f0 BS |
110 | taken. For more details see mount(8). |
111 | .TP | |
112 | .BR -V , " \-\-version" | |
b4362b6f | 113 | Display version information and exit. |
7e658c15 OO |
114 | .SH EXAMPLES |
115 | .TP | |
d9921b2a | 116 | .BR "wipefs /dev/sda*" |
fcf841f8 | 117 | Prints information about sda and all partitions on sda. |
d9921b2a | 118 | .TP |
7e658c15 OO |
119 | .BR "wipefs --all --backup /dev/sdb" |
120 | Erases all signatures from the device /dev/sdb and creates a signature backup | |
121 | file ~/wipefs-sdb-<offset>.bak for each signature. | |
122 | .TP | |
123 | .BR "dd if=~/wipefs-sdb-0x00000438.bak of=/dev/sdb seek=$((0x00000438)) bs=1 conv=notrunc" | |
92f1c5ab | 124 | Restores an ext2 signature from the backup file ~/wipefs-sdb-0x00000438.bak. |
c49057d2 | 125 | .SH AUTHOR |
1faf44f0 | 126 | Karel Zak <kzak@redhat.com> |
ddfeda98 | 127 | .SH ENVIRONMENT |
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128 | .IP LIBBLKID_DEBUG=all |
129 | enables libblkid debug output. | |
c49057d2 | 130 | .SH SEE ALSO |
66083665 | 131 | .BR blkid (8), |
c49057d2 | 132 | .BR findfs (8) |
9c91fc03 BS |
133 | .SH AVAILABILITY |
134 | The wipefs command is part of the util-linux package and is available from | |
d673b74e | 135 | https://www.kernel.org/pub/linux/utils/util-linux/. |