wipefs(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | ENVIRONMENT | EXAMPLE | AUTHORS | SEE ALSO | AVAILABILITY | COLOPHON

WIPEFS(8)                 System Administration                WIPEFS(8)

NAME         top

       wipefs - wipe a signature from a device

SYNOPSIS         top

       wipefs [options] device...

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

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

DESCRIPTION         top

       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. The ioctl
       is called as the last step and when all specified signatures from
       all specified devices are already erased.  This feature can be
       used to wipe content on partitions devices as well as partition
       table on a disk device, for example by wipefs -a /dev/sdc1
       /dev/sdc2 /dev/sdc.

       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         top

       -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 EXAMPLE 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.

       --lock[=mode]
              Use exclusive BSD lock for device or file it operates.
              The optional argument mode can be yes, no (or 1 and 0) or
              nonblock.  If the mode argument is omitted, it defaults to
              "yes".  This option overwrites environment variable
              $LOCK_BLOCK_DEVICE.  The default is not to use any lock at
              all, but it's recommended to avoid collisions with udevd
              or other tools.

       -i, --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.

ENVIRONMENT         top

       LIBBLKID_DEBUG=all
              enables libblkid debug output.

       LOCK_BLOCK_DEVICE=<mode>
              use exclusive BSD lock.  The mode is "1" or "0".  See
              --lock for more details.

EXAMPLE         top

       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.

AUTHORS         top

       Karel Zak <kzak@redhat.com>

SEE ALSO         top

       blkid(8), findfs(8)

AVAILABILITY         top

       The wipefs command is part of the util-linux package and is
       available from
       https://www.kernel.org/pub/linux/utils/util-linux/.

COLOPHON         top

       This page is part of the util-linux (a random collection of Linux
       utilities) project.  Information about the project can be found
       at ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩.  If you
       have a bug report for this manual page, send it to
       util-linux@vger.kernel.org.  This page was obtained from the
       project's upstream Git repository
       ⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
       2021-03-21.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-03-19.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

util-linux                    December 2014                    WIPEFS(8)

Pages that refer to this page: systemd.mount(5)systemd.swap(5)blkid(8)btrfs-device(8)cfdisk(8)fdisk(8)mkfs.btrfs(8)sfdisk(8)