NAME

       wipefs - wipe a signature from a device

SYNOPSIS

       wipefs [options] device...

       wipefs [--backup] -o offset device...

       wipefs [--backup] -a device...

DESCRIPTION

       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  any  options, wipefs lists all visible filesystems and the offsets of
       their basic signatures.  The default output is subject to change.  So  whenever  possible,
       you should avoid using default outputs in your scripts.  Always explicitly define expected
       columns by using --output columns-list in environments where a stable output is required.

       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 (e.g. FAT, ZFS, GPT).  The wipefs command (since v2.31) lists all the offset  where
       a magic strings have been detected.

       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-<devname>-<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.

       -J, --json
              Use JSON output format.

       -n, --noheadings
              Do not print a header line.

       -O, --output list
              Specify  which  output columns to print.  Use --help to get a list of all supported
              columns.

       -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 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, --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.

EXAMPLES

       wipefs /dev/sda*
              Prints information about sda and all partitions on sda.

       wipefs --all --backup /dev/sdb
              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 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 ALSO

       blkid(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/.