wipefs(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | ENVIRONMENT | EXAMPLES | AUTHORS | SEE ALSO | REPORTING BUGS | AVAILABILITY

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(3) 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(2) 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(3) debug output.

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

EXAMPLES         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)

REPORTING BUGS         top

       For bug reports, use the issue tracker at
       https://github.com/karelzak/util-linux/issues.

AVAILABILITY         top

       The wipefs command is part of the util-linux package which can be
       downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>. 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
       2021-06-20. (At that time, the date of the most recent commit
       that was found in the repository was 2021-06-18.) 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 2.37.85-637cc       2021-04-02                      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)