1WIPEFS(8) System Administration WIPEFS(8)
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6 wipefs - wipe a signature from a device
7
9 wipefs [options] device...
10 wipefs [--backup] -o offset device...
12 wipefs [--backup] -a device...
14
16 wipefs can erase filesystem, raid or partition-table signatures (magic
17 strings) from the specified device to make the signatures invisible for
18 libblkid. wipefs does not erase the filesystem itself nor any other
19 data from the device.
20 When used without any options, wipefs lists all visible filesystems and
22 the offsets of their basic signatures. The default output is subject to
23 change. So whenever possible, you should avoid using default outputs in
24 your scripts. Always explicitly define expected columns by using
25 --output columns-list in environments where a stable output is
26 required.
27 wipefs calls the BLKRRPART ioctl when it has erased a partition-table
29 signature to inform the kernel about the change. The ioctl is called as
30 the last step and when all specified signatures from all specified
31 devices are already erased. This feature can be used to wipe content on
32 partitions devices as well as partition table on a disk device, for
33 example by wipefs -a /dev/sdc1 /dev/sdc2 /dev/sdc.
34 Note that some filesystems and some partition tables store more magic
36 strings on the device (e.g., FAT, ZFS, GPT). The wipefs command (since
37 v2.31) lists all the offset where a magic strings have been detected.
38 When option -a is used, all magic strings that are visible for
40 libblkid(3) are erased. In this case the wipefs scans the device again
41 after each modification (erase) until no magic string is found.
42 Note that by default wipefs does not erase nested partition tables on
44 non-whole disk devices. For this the option --force is required.
45
47 -a, --all
48 Erase all available signatures. The set of erased signatures can be
49 restricted with the -t option.
50 -b, --backup
52 Create a signature backup to the file
53 $HOME/wipefs-<devname>-<offset>.bak. For more details see the
54 EXAMPLE section.
55 -f, --force
57 Force erasure, even if the filesystem is mounted. This is required
58 in order to erase a partition-table signature on a block device.
59 -h, --help
61 Display help text and exit.
62 -J, --json
64 Use JSON output format.
65 --lock[=mode]
67 Use exclusive BSD lock for device or file it operates. The optional
68 argument mode can be yes, no (or 1 and 0) or nonblock. If the mode
69 argument is omitted, it defaults to "yes". This option overwrites
70 environment variable $LOCK_BLOCK_DEVICE. The default is not to use
71 any lock at all, but it’s recommended to avoid collisions with
72 udevd or other tools.
73 -i, --noheadings
75 Do not print a header line.
76 -O, --output list
78 Specify which output columns to print. Use --help to get a list of
79 all supported columns.
80 -n, --no-act
82 Causes everything to be done except for the write(2) call.
83 -o, --offset offset
85 Specify the location (in bytes) of the signature which should be
86 erased from the device. The offset number may include a "0x"
87 prefix; then the number will be interpreted as a hex value. It is
88 possible to specify multiple -o options.
89 The offset argument may be followed by the multiplicative suffixes
91 KiB (=1024), MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB,
92 ZiB and YiB (the "iB" is optional, e.g., "K" has the same meaning
93 as "KiB"), or the suffixes KB (=1000), MB (=1000*1000), and so on
94 for GB, TB, PB, EB, ZB and YB.
95 -p, --parsable
97 Print out in parsable instead of printable format. Encode all
98 potentially unsafe characters of a string to the corresponding hex
99 value prefixed by '\x'.
100 -q, --quiet
102 Suppress any messages after a successful signature wipe.
103 -t, --types list
105 Limit the set of printed or erased signatures. More than one type
106 may be specified in a comma-separated list. The list or individual
107 types can be prefixed with 'no' to specify the types on which no
108 action should be taken. For more details see mount(8).
109 -V, --version
111 Display version information and exit.
112
114 LIBBLKID_DEBUG=all
115 enables libblkid(3) debug output.
116 LOCK_BLOCK_DEVICE=<mode>
118 use exclusive BSD lock. The mode is "1" or "0". See --lock for more
119 details.
120
122 wipefs /dev/sda*
123 Prints information about sda and all partitions on sda.
124 wipefs --all --backup /dev/sdb
126 Erases all signatures from the device /dev/sdb and creates a
127 signature backup file ~/wipefs-sdb-<offset>.bak for each signature.
128 dd if=~/wipefs-sdb-0x00000438.bak of=/dev/sdb seek=$0x00000438 bs=1
130 conv=notrunc
131 Restores an ext2 signature from the backup file
132 ~/wipefs-sdb-0x00000438.bak.
133
135 Karel Zak <kzak@redhat.com>
136
138 blkid(8), findfs(8)
139
141 For bug reports, use the issue tracker at
142 https://github.com/karelzak/util-linux/issues.
143
145 The wipefs command is part of the util-linux package which can be
146 downloaded from Linux Kernel Archive
147 <https://www.kernel.org/pub/linux/utils/util-linux/>.
148util-linux 2.37.2 2021-06-02 WIPEFS(8)