sfdisk(8) — Linux manual page


SFDISK(8)                   System Administration                  SFDISK(8)

NAME         top

       sfdisk - display or manipulate a disk partition table

SYNOPSIS         top

       sfdisk [options] device [-N partition-number]

       sfdisk [options] command

DESCRIPTION         top

       sfdisk is a script-oriented tool for partitioning any block device.
       It runs in interactive mode if executed on a terminal (stdin refers
       to a terminal).

       Since version 2.26 sfdisk supports MBR (DOS), GPT, SUN and SGI disk
       labels, but no longer provides any functionality for CHS (Cylinder-
       Head-Sector) addressing.  CHS has never been important for Linux, and
       this addressing concept does not make any sense for new devices.

       sfdisk (since version 2.26) aligns the start and end of partitions to
       block-device I/O limits when relative sizes are specified, when the
       default values are used or when multiplicative suffixes (e.g., MiB)
       are used for sizes.  It is possible that partition size will be
       optimized (reduced or enlarged) due to alignment if the start offset
       is specified exactly in sectors and partition size relative or by
       multiplicative suffixes.

       The recommended way is not to specify start offsets at all and
       specify partition size in MiB, GiB (or so).  In this case sfdisk
       aligns all partitions to block-device I/O limits (or when I/O limits
       are too small then to megabyte boundary to keep disk layout
       portable).  If this default behaviour is unwanted (usually for very
       small partitions) then specify offsets and sizes in sectors.  In this
       case sfdisk entirely follows specified numbers without any

       sfdisk does not create the standard system partitions for SGI and SUN
       disk labels like fdisk(8) does.  It is necessary to explicitly create
       all partitions including whole-disk system partitions.

       sfdisk uses BLKRRPART (reread partition table) ioctl to make sure
       that the device is not used by system or other tools (see also --no-
       reread).  It's possible that this feature or another sfdisk activity
       races with udevd.  The recommended way how to avoid possible
       collisions is to use --lock option.  The exclusive lock will cause
       udevd to skip the event handling on the device.

       The sfdisk prompt is only a hint for users and a displayed partition
       number does not mean that the same partition table entry will be
       created (if -N not specified), especially for tables with gaps.

COMMANDS         top

       The commands are mutually exclusive.

       [-N partition-number] device
              The default sfdisk command is to read the specification for
              the desired partitioning of device from standard input, and
              then create a partition table according to the specification.
              See below for the description of the input format.  If
              standard input is a terminal, then sfdisk starts an
              interactive session.

              If the option -N is specified, then the changes are applied to
              the partition addressed by partition-number.  The unspecified
              fields of the partition are not modified.

              Note that it's possible to address an unused partition with
              -N.  For example, an MBR always contains 4 partitions, but the
              number of used partitions may be smaller.  In this case sfdisk
              follows the default values from the partition table and does
              not use built-in defaults for the unused partition given with
              -N.  See also --append.

       -A, --activate device [partition-number...]
              Switch on the bootable flag for the specified partitions and
              switch off the bootable flag on all unspecified partitions.
              The special placeholder '-' may be used instead of the
              partition numbers to switch off the bootable flag on all

              The activation command is supported for MBR and PMBR only.  If
              a GPT label is detected, then sfdisk prints warning and
              automatically enters PMBR.

              If no partition-number is specified, then list the partitions
              with an enabled flag.

       --delete device [partition-number...]
              Delete all or the specified partitions.

       -d, --dump device
              Dump the partitions of a device in a format that is usable as
              input to sfdisk.  See the section BACKING UP THE PARTITION

       -g, --show-geometry [device...]
              List the geometry of all or the specified devices. For
              backward compatibility the deprecated option
              --show-pt-geometry have the same meaning as this one.

       -J, --json device
              Dump the partitions of a device in JSON format.  Note that
              sfdisk is not able to use JSON as input format.

       -l, --list [device...]
              List the partitions of all or the specified devices.  This
              command can be used together with --verify.

       -F, --list-free [device...]
              List the free unpartitioned areas on all or the specified

       --part-attrs device partition-number [attributes]
              Change the GPT partition attribute bits.  If attributes is not
              specified, then print the current partition settings.

              The attributes argument is a comma- or space-delimited list of
              bits.  The currently supported attribute bits are:
              RequiredPartition, NoBlockIOProtocol, LegacyBIOSBootable and
              GUID-specific bits in the range from 48 to 63.  For example,
              the string "RequiredPartition,50,51" sets three bits.

       --part-label device partition-number [label]
              Change the GPT partition name (label).  If label is not
              specified, then print the current partition label.

       --part-type device partition-number [type]
              Change the partition type.  If type is not specified, then
              print the current partition type.

              The type argument is hexadecimal for MBR, GUID for GPT, type
              alias (e.g. "linux") or type shortcut (e.g. 'L').  For
              backward compatibility the options -c and --id have the same
              meaning as this one.

       --part-uuid device partition-number [uuid]
              Change the GPT partition UUID.  If uuid is not specified, then
              print the current partition UUID.

       --disk-id device [id]
              Change the disk identifier.  If id is not specified, then
              print the current identifier.  The identifier is UUID for GPT
              or unsigned integer for MBR.

       -r, --reorder device
              Renumber the partitions, ordering them by their start offset.

       -s, --show-size [device...]
              List the sizes of all or the specified devices in units of
              1024 byte size.  This command is DEPRECATED in favour of

       -T, --list-types
              Print all supported types for the current disk label or the
              label specified by --label.

       -V, --verify [device...]
              Test whether the partition table and partitions seem correct.

       --relocate oper device
              Relocate partition table header. This command is currently
              supported for GPT header only.  The argument oper can be:

                     Move GPT backup header to the standard location at the
                     end of the device.

                     Move GPT backup header behind the last partition. Note
                     that UEFI standard requires the backup header at the
                     end of the device and partitioning tools can
                     automatically relocate the header to follow the

OPTIONS         top

       -a, --append
              Don't create a new partition table, but only append the
              specified partitions.

              Note that unused partition maybe be re-used in this case
              although it is not the last partition in the partition table.
              See also -N to specify entry in the partition table.

       -b, --backup
              Back up the current partition table sectors before starting
              the partitioning.  The default backup file name is
              ~/sfdisk-<device>-<offset>.bak; to use another name see option
              -O, --backup-file.

              Colorize the output.  The optional argument when can be auto,
              never or always.  If the when argument is omitted, it defaults
              to auto.  The colors can be disabled; for the current built-in
              default see the --help output.  See also the COLORS section.

       -f, --force
              Disable all consistency checking.

              Deprecated and ignored option.  Partitioning that is
              compatible with Linux (and other modern operating systems) is
              the default.

              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.

       -n, --no-act
              Do everything except writing to the device.

              Do not check through the re-read-partition-table ioctl whether
              the device is in use.

              Don't tell the kernel about partition changes. This option is
              recommended together with --no-reread to modify a partition on
              used disk. The modified partition should not be used (e.g.,

       -O, --backup-file path
              Override the default backup file name.  Note that the device
              name and offset are always appended to the file name.

              Move data after partition relocation, for example when moving
              the beginning of a partition to another place on the disk.
              The size of the partition has to remain the same, the new and
              old location may overlap.  This option requires option -N in
              order to be processed on one specific partition only.

              The optional path specifies log file name. The log file
              contains information about all read/write operations on the
              partition data. The word "@default" as a path forces sfdisk to
              use ~/sfdisk-<devname>.move for the log.  The log is optional
              since v2.35.

              Note that this operation is risky and not atomic. Don't forget
              to backup your data!

              See also --move-use-fsync.

              In the example below, the first command creates a 100MiB free
              area before the first partition and moves the data it contains
              (e.g., a filesystem), the next command creates a new partition
              from the free space (at offset 2048), and the last command
              reorders partitions to match disk order (the original sdc1
              will become sdc2).

              echo '+100M,' | sfdisk --move-data /dev/sdc -N 1
              echo '2048,' | sfdisk /dev/sdc --append
              sfdisk /dev/sdc --reorder

              Use the fsync(2) system call after each write when moving data
              to a new location by --move-data.

       -o, --output list
              Specify which output columns to print.  Use --help to get a
              list of all supported columns.

              The default list of columns may be extended if list is
              specified in the format +list (e.g., -o +UUID).

       -q, --quiet
              Suppress extra info messages.

       -u, --unit S
              Deprecated option.  Only the sector unit is supported. This
              option is not supported when using the --show-size command.

       -X, --label type
              Specify the disk label type (e.g., dos, gpt, ...).  If this
              option is not given, then sfdisk defaults to the existing
              label, but if there is no label on the device yet, then the
              type defaults to dos. The default or the current label may be
              overwritten by the "label: <name>" script header line. The
              option --label does not force sfdisk to create empty disk
              label (see the EMPTY DISK LABEL section below).

       -Y, --label-nested type
              Force editing of a nested disk label.  The primary disk label
              has to exist already.  This option allows editing for example
              a hybrid/protective MBR on devices with GPT.

       -w, --wipe when
              Wipe filesystem, RAID and partition-table signatures from the
              device, in order to avoid possible collisions.  The argument
              when can be auto, never or always.  When this option is not
              given, the default is auto, in which case signatures are wiped
              only when in interactive mode; except the old partition-table
              signatures which are always wiped before create a new
              partition-table if the argument when is not never. In all
              cases detected signatures are reported by warning messages
              before a new partition table is created.  See also the
              wipefs(8) command.

       -W, --wipe-partitions when
              Wipe filesystem, RAID and partition-table signatures from a
              newly created partitions, in order to avoid possible
              collisions.  The argument when can be auto, never or always.
              When this option is not given, the default is auto, in which
              case signatures are wiped only when in interactive mode and
              after confirmation by user.  In all cases detected signatures
              are reported by warning messages after a new partition is
              created.  See also wipefs(8) command.

       -v, --version
              Display version information and exit.

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

INPUT FORMATS         top

       sfdisk supports two input formats and generic header lines.

   Header lines
       The optional header lines specify generic information that apply to
       the partition table.  The header-line format is:

       <name>: <value>

       The currently recognized headers are:

       unit   Specify the partitioning unit.  The only supported unit is

       label  Specify the partition table type.  For example dos or gpt.

              Specify the partition table identifier.  It should be a
              hexadecimal number (with a 0x prefix) for MBR and a UUID for

              Specify the first usable sector for GPT partitions.

              Specify the last usable sector for GPT partitions.

              Specify the maximal number of GPT partitions.

       grain  Specify minimal size in bytes used to calculate partitions
              alignment.  The default is 1MiB and it's strongly recommended
              to use the default.  Do not modify this variable if you're not

              Specify sector size. This header is informative only and it is
              not used when sfdisk creates a new partition table, in this
              case the real device specific value is always used and sector
              size from the dump is ignored.

       Note that it is only possible to use header lines before the first
       partition is specified in the input.

   Unnamed-fields format

              start size type bootable

       where each line fills one partition descriptor.

       Fields are separated by whitespace, comma or semicolon possibly
       followed by whitespace; initial and trailing whitespace is ignored.
       Numbers can be octal, decimal or hexadecimal; decimal is the default.
       When a field is absent, empty or specified as '-' a default value is
       used.  But when the -N option (change a single partition) is given,
       the default for each field is its previous value.

       The default value of start is the first non-assigned sector aligned
       according to device I/O limits.  The default start offset for the
       first partition is 1 MiB.  The offset may be followed by the
       multiplicative suffixes (KiB, MiB, GiB, TiB, PiB, EiB, ZiB and YiB)
       then the number is interpreted as offset in bytes.

       The default value of size indicates "as much as possible"; i.e.,
       until the next partition or end-of-device.  A numerical argument is
       by default interpreted as a number of sectors, however if the size is
       followed by one of the multiplicative suffixes (KiB, MiB, GiB, TiB,
       PiB, EiB, ZiB and YiB) then the number is interpreted as the size of
       the partition in bytes and it is then aligned according to the device
       I/O limits.  A '+' can be used instead of a number to enlarge the
       partition as much as possible.  Note '+' is equivalent to the default
       behaviour for a new partition; existing partitions will be resized as

       The partition type is given in hex for MBR (DOS) where 0x prefix is
       optional; a GUID string for GPT; a shortcut or an alias. It's
       recommended to use two letters for MBR hex codes to avoid collision
       between deprecated shortcut 'E' and '0E' MBR hex code. For backward
       compatibility sfdisk tries to interpret type as a shortcut as a first
       possibility in partitioning scripts although on other places (e.g.
       --part-type command) it tries shortcuts as the last possibility.

       Since v2.36 libfdisk supports partition type aliases as extension to
       shortcuts. The alias is a simple human readable word (e.g. "linux").

       Supported shortcuts and aliases:

       L - alias 'linux'
              Linux; means 83 for MBR and
              0FC63DAF-8483-4772-8E79-3D69D8477DE4 for GPT.

       S - alias 'swap'
              swap area; means 82 for MBR and 0657FD6D-
              A4AB-43C4-84E5-0933C84B4F4F for GPT

       Ex - alias 'extended'
              MBR extended partition; means 05 for MBR.  The original
              shortcut 'E' is deprecated due to collision with 0x0E MBR
              partition type.

       H - alias 'home'
              home partition; means 933AC7E1-2EB4-4F13-B844-0E14E2AEF915 for

       U - alias 'uefi'
              EFI System partition, means EF for MBR and
              C12A7328-F81F-11D2-BA4B-00A0C93EC93B for GPT

       R - alias 'raid'
              Linux RAID; means FD for MBR and A19D880F-05FC-4D3B-
              A006-743F0F84911E for GPT

       V - alias 'lvm'
              LVM; means 8E for MBR and E6D6D379-F507-44C2-A23C-238F2A3DF928
              for GPT

       The default type value is linux

       The shortcut 'X' for Linux extended partition (85) is deprecated in
       favour of 'Ex'.

       bootable is specified as [*|-], with as default not-bootable.  The
       value of this field is irrelevant for Linux - when Linux runs it has
       been booted already - but it might play a role for certain boot
       loaders and for other operating systems.

   Named-fields format
       This format is more readable, robust, extensible and allows
       specifying additional information (e.g., a UUID).  It is recommended
       to use this format to keep your scripts more readable.

              [device :] name[=value], ...

       The device field is optional.  sfdisk extracts the partition number
       from the device name.  It allows specifying the partitions in random
       order.  This functionality is mostly used by --dump.  Don't use it if
       you are not sure.

       The value can be between quotation marks (e.g., name="This is
       partition name").  The currently supported fields are:

              The first non-assigned sector aligned according to device I/O
              limits.  The default start offset for the first partition is 1
              MiB. The offset may be followed by the multiplicative suffixes
              (KiB, MiB, GiB, TiB, PiB, EiB, ZiB and YiB) then the number is
              interpreted as offset in bytes.

              Specify the partition size in sectors.  The number may be
              followed by the multiplicative suffixes (KiB, MiB, GiB, TiB,
              PiB, EiB, ZiB and YiB), then it's interpreted as size in bytes
              and the size is aligned according to device I/O limits.

              Mark the partition as bootable.

              Partition attributes, usually GPT partition attribute bits.
              See --part-attrs for more details about the GPT-bits string

              GPT partition UUID.

              GPT partition name.

              A hexadecimal number (without 0x) for an MBR partition, a GUID
              for a GPT partition, or a shortcut as for unnamed-fields
              format.  For backward compatibility the Id= field has the same

EMPTY DISK LABEL         top

       sfdisk does not create partition table without partitions by default.
       The lines with partitions are expected in the script by default. The
       empty partition table has to be explicitly requested by "label:
       <name>" script header line without any partitions lines. For example:

              echo 'label: gpt' | sfdisk /dev/sdb

       creates empty GPT partition table. Note that the --append disables
       this feature.


       It is recommended to save the layout of your devices.  sfdisk
       supports two ways.

       Use the --dump option to save a description of the device layout to a
       text file.  The dump format is suitable for later sfdisk input.  For

              sfdisk --dump /dev/sda > sda.dump

       This can later be restored by:

              sfdisk /dev/sda < sda.dump

       If you want to do a full (binary) backup of all sectors where the
       partition table is stored, then use the --backup option.  It writes
       the sectors to ~/sfdisk-<device>-<offset>.bak files.  The default
       name of the backup file can be changed with the --backup-file option.
       The backup files contain only raw data from the device.  Note that
       the same concept of backup files is used by wipefs(8).  For example:

              sfdisk --backup /dev/sda

       The GPT header can later be restored by:

              dd  if=~/sfdisk-sda-0x00000200.bak  of=/dev/sda  \
                seek=$((0x00000200))  bs=1  conv=notrunc

       Note that sfdisk since version 2.26 no longer provides the -I option
       to restore sectors.  dd(1) provides all necessary functionality.

COLORS         top

       Implicit coloring can be disabled by an empty file /etc/terminal-

       See terminal-colors.d(5) for more details about colorization
       configuration. The logical color names supported by sfdisk are:

       header The header of the output tables.

       warn   The warning messages.

              The welcome message.

ENVIRONMENT         top

              enablescw sfdisk debug output.

              enables libfdisk debug output.

              enables libblkid debug output.

              enables libsmartcols debug output.

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

NOTES         top

       Since version 2.26 sfdisk no longer provides the -R or --re-read
       option to force the kernel to reread the partition table.  Use
       blockdev --rereadpt instead.

       Since version 2.26 sfdisk does not provide the --DOS, --IBM,
       --DOS-extended, --unhide, --show-extended, --cylinders, --heads,
       --sectors, --inside-outer, --not-inside-outer options.

AUTHORS         top

       Karel Zak <kzak@redhat.com>

       The current sfdisk implementation is based on the original sfdisk
       from Andries E. Brouwer.

SEE ALSO         top

       fdisk(8), cfdisk(8), parted(8), partprobe(8), partx(8)

AVAILABILITY         top

       The sfdisk 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
       2020-08-13.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-08-12.)  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

util-linux                        June 2015                        SFDISK(8)

Pages that refer to this page: repart.d(5)cfdisk(8)fdisk(8)