#Bash 的 wipefs 命令

WIPEFS(8)                    System Administration                   WIPEFS(8)

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. 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
       -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.

       -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).

       -h, --help
           Display help text and exit.

       -V, --version
           Print version and exit.

ENVIRONMENT
       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
       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
       Karel Zak <[email protected]>

SEE ALSO
       blkid(8), findfs(8)

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

AVAILABILITY
       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/>.

util-linux 2.39.3                 2023-10-23                         WIPEFS(8)