NAME

       wipefs - wipe a signature from a device

SYNOPSIS

       wipefs [-ahnpqtV] [-o offset] 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.

       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.

       When option -a is used, all magic strings that are visible for libblkid are erased.

       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.

       -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 --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
       ftp://ftp.kernel.org/pub/linux/utils/util-linux/.