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wipefs — wipe a signature from a device
wipefs [−ahnpqtV] [ −o offset ] device...
wipefs 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 options −a or −o, 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 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 wipefs -o offset the same filesystem or
partition table will still be visible by another magic string
on another offset.
When used with option −a, all magic strings that are visible
for libblkid are erased.
−a,
−−allErase all available signatures. The set of erased
signatures can be restricted with the −t list option.
−b,
−−backupCreate a signature backup to the file $HOME/wipefs-<devname>-<offset>.bak. For more details see EXAMPLES section.
−f,
−−forceForce erasure, even if the filesystem is mounted. This is required in order to erase the partition table on a block device.
−h,
−−helpDisplay help text and exit.
−n,
−−no−actCauses everything to be done except for the write() call.
−o,
−−offset offsetSpecify the location (in bytes) of the signature
which should be erased from the device. The offset number may include
a "0x" prefix; then the number will be interpreted as a
hex value. It is possible to specify multiple
−o
options.
The offset
argument may be followed by the multiplicative suffixes
KiB (=1024), MiB (=1024*1024), and so on for GiB, TiB,
PiB, EiB, ZiB and YiB (the "iB" is optional, e.g. "K"
has the same meaning as "KiB"), or the suffixes KB
(=1000), MB (=1000*1000), and so on for GB, TB, PB, EB,
ZB and YB.
−p,
−−parsablePrint out in parsable instead of printable format. Encode all potentially unsafe characters of a string to the corresponding hex value prefixed by '\x'.
−q,
−−quietSuppress output messages after successful signature wipe.
−t,
−−types listLimit the set of printed or erased signatures. More than one type may be specified in a comma-separated list. The list or individual types can be prefixed with 'no' to specify the types on which no action should be taken. For more details see mount(8).
−V,
−−versionDisplay version information and exit.
Erases all signatures from the device /dev/sdb and creates a signature backup file ~/wipefs-sdb-<offset>.bak for each signature.
dd
if=~/wipefs-sdb-0x00000438.bak of=/dev/sdb
seek=$((0x00000438)) bs=1
conv=notrunc()Restores ext2 signature from the backup file ~/wipefs-sdb-0x00000438.bak.