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/.