1WIPEFS(8) System Administration WIPEFS(8)
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6 wipefs - wipe a signature from a device
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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
23 to change. So whenever possible, you should avoid using default out‐
24 puts in your scripts. Always explicitly define expected columns by
25 using --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
32 on 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 libblkid
40 are erased. In this case the wipefs scans the device again after each
41 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
48 -a, --all
49 Erase all available signatures. The set of erased signatures
50 can be restricted with the -t option.
51 -b, --backup
53 Create a signature backup to the file $HOME/wipefs-<dev‐
54 name>-<offset>.bak. For more details see the EXAMPLE section.
55 -f, --force
57 Force erasure, even if the filesystem is mounted. This is
58 required in order to erase a partition-table signature on a
59 block device.
60 -h, --help
62 Display help text and exit.
63 -J, --json
65 Use JSON output format.
66 --lock[=mode]
68 Use exclusive BSD lock for device or file it operates. The
69 optional argument mode can be yes, no (or 1 and 0) or nonblock.
70 If the mode argument is omitted, it defaults to "yes". This
71 option overwrites environment variable $LOCK_BLOCK_DEVICE. The
72 default is not to use any lock at all, but it's recommended to
73 avoid collisions with udevd or other tools.
74 -i, --noheadings
76 Do not print a header line.
77 -O, --output list
79 Specify which output columns to print. Use --help to get a list
80 of all supported columns.
81 -n, --no-act
83 Causes everything to be done except for the write() call.
84 -o, --offset offset
86 Specify the location (in bytes) of the signature which should be
87 erased from the device. The offset number may include a "0x"
88 prefix; then the number will be interpreted as a hex value. It
89 is possible to specify multiple -o options.
90 The offset argument may be followed by the multiplicative suf‐
92 fixes KiB (=1024), MiB (=1024*1024), and so on for GiB, TiB,
93 PiB, EiB, ZiB and YiB (the "iB" is optional, e.g., "K" has the
94 same meaning as "KiB"), or the suffixes KB (=1000), MB
95 (=1000*1000), and so on for GB, TB, PB, EB, ZB and YB.
96 -p, --parsable
98 Print out in parsable instead of printable format. Encode all
99 potentially unsafe characters of a string to the corresponding
100 hex value prefixed by '\x'.
101 -q, --quiet
103 Suppress any messages after a successful signature wipe.
104 -t, --types list
106 Limit the set of printed or erased signatures. More than one
107 type may be specified in a comma-separated list. The list or
108 individual types can be prefixed with 'no' to specify the types
109 on which no action should be taken. For more details see
110 mount(8).
111 -V, --version
113 Display version information and exit.
114
116 LIBBLKID_DEBUG=all
117 enables libblkid debug output.
118 LOCK_BLOCK_DEVICE=<mode>
120 use exclusive BSD lock. The mode is "1" or "0". See --lock for
121 more details.
122
124 wipefs /dev/sda*
125 Prints information about sda and all partitions on sda.
126 wipefs --all --backup /dev/sdb
128 Erases all signatures from the device /dev/sdb and creates a
129 signature backup file ~/wipefs-sdb-<offset>.bak for each signa‐
130 ture.
131 dd if=~/wipefs-sdb-0x00000438.bak of=/dev/sdb seek=$((0x00000438)) bs=1
133 conv=notrunc
134 Restores an ext2 signature from the backup file ~/wipefs-
135 sdb-0x00000438.bak.
136
138 Karel Zak <kzak@redhat.com>
139
141 blkid(8), findfs(8)
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144 The wipefs command is part of the util-linux package and is available
145 from https://www.kernel.org/pub/linux/utils/util-linux/.
146util-linux December 2014 WIPEFS(8)