WIPEFS(8) System Administration WIPEFS(8)NAMEwipefs - wipe a signature from a device
SYNOPSISwipefs [-ahnpqtV] [-o offset] device...
DESCRIPTIONwipefs can erase filesystem, raid or partition-table signatures (magic
strings) from the specified device to make the signatures invisible for
libblkid.
wipefs does not erase the filesystem itself nor any other data from the
device. When used without any options, wipefs lists all visible
filesystems and the offsets of their basic signatures.
wipefs calls the BLKRRPART ioctl when it has erased a partition-table
signature to inform the kernel about the change.
Note that some filesystems and some partition tables store more magic
strings on the device. The wipefs command lists only the first offset
where a magic string has been detected. The device is not scanned for
additional magic strings for the same filesystem. It is possible that
after a wipefs-o offset the same filesystem or partition table will
still be visible because of another magic string on another offset. The
option --no-act is also affected by this behavior and only the first
magic string for the filesystem is reported.
When option -a is used, all magic strings that are visible for libblkid
are erased. In this case the wipefs scans the device again after each
modification (erase) until no magic string is found.
Note that by default wipefs does not erase nested partition tables on
non-whole disk devices. For this the option --force is required.
OPTIONS-a, --all
Erase all available signatures. The set of erased signatures
can be restricted with the -t option.
-b, --backup
Create a signature backup to the file $HOME/wipefs-<dev‐
name>-<offset>.bak. For more details see the EXAMPLES section.
-f, --force
Force erasure, even if the filesystem is mounted. This is
required in order to erase a partition-table signature on a
block device.
-h, --help
Display help text and exit.
-n, --no-act
Causes everything to be done except for the write() call.
-o, --offset offset
Specify the location (in bytes) of the signature which should be
erased from the device. The offset number may include a "0x"
prefix; then the number will be interpreted as a hex value. It
is possible to specify multiple -o options.
The offset argument may be followed by the multiplicative suf‐
fixes KiB (=1024), MiB (=1024*1024), and so on for GiB, TiB,
PiB, EiB, ZiB and YiB (the "iB" is optional, e.g. "K" has the
same meaning as "KiB"), or the suffixes KB (=1000), MB
(=1000*1000), and so on for GB, TB, PB, EB, ZB and YB.
-p, --parsable
Print out in parsable instead of printable format. Encode all
potentially unsafe characters of a string to the corresponding
hex value prefixed by '\x'.
-q, --quiet
Suppress any messages after a successful signature wipe.
-t, --types list
Limit the set of printed or erased signatures. More than one
type may be specified in a comma-separated list. The list or
individual types can be prefixed with 'no' to specify the types
on which no action should be taken. For more details see
mount(8).
-V, --version
Display version information and exit.
EXAMPLESwipefs--all --backup /dev/sdb
Erases all signatures from the device /dev/sdb and creates a
signature backup file ~/wipefs-sdb-<offset>.bak for each signa‐
ture.
dd if=~/wipefs-sdb-0x00000438.bak of=/dev/sdb seek=$((0x00000438)) bs=1
conv=notrunc
Restores an ext2 signature from the backup file ~/wipefs-
sdb-0x00000438.bak.
AUTHOR
Karel Zak <kzak@redhat.com>
ENVIRONMENT
LIBBLKID_DEBUG=all
enables libblkid debug output.
SEE ALSOblkid(8), findfs(8)AVAILABILITY
The wipefs command is part of the util-linux package and is available
from https://www.kernel.org/pub/linux/utils/util-linux/.
util-linux December 2014 WIPEFS(8)
