Provided by: fdisk_2.36.1-8ubuntu1_amd64 bug


       sfdisk - display or manipulate a disk partition table


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

       sfdisk [options] command


       sfdisk  is  a  script-oriented  tool  for  partitioning  any  block  device.   It  runs in
       interactive mode if executed on 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 align 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 optimization.

       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.


       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

              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

       -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 GPT label is
              detected than sfdisk prints warning and automatically enter 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 TABLE.

       -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 devices.

       --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  numbers  or  bit  names.   For  example,  the  string
              "RequiredPartition,50,51"  sets three bits.  The currently supported attribute bits

              Bit 0 (RequiredPartition)
                     If this bit is set, the partition is required for the platform to  function.
                     The  creator of the partition indicates that deletion or modification of the
                     contents can result in loss of platform features or failure for the platform
                     to boot or operate. The system cannot function normally if this partition is
                     removed, and it should be considered part of the hardware of the system.

              Bit 1 (NoBlockIOProtocol)
                     EFI firmware should ignore the content of the partition and not try to  read
                     from it.

              Bit 2 (LegacyBIOSBootable)
                     The partition may be bootable by legacy BIOS firmware.

              Bits 3-47
                     Undefined and must be zero. Reserved for expansion by future versions of the
                     UEFI specification.

              Bits 48-63
                     Reserved for GUID specific use. The use of these bits will vary depending on
                     the  partition  type.   For  example Microsoft uses bit 60 to indicate read-
                     only, 61 for shadow copy of another partition, 62 for hidden partitions  and
                     63 to disable automount.

       --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 blockdev(8).

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

       -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 standard.


       -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

              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., mounted).

       -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 fsync system call after each  write  when  move  data  to  a  new  location  by

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

              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 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.


       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 sectors.

                     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 GPT.

                            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 sure.

                            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

              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 required.

              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

                     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 GPT

                     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

              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

                            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 format.

                            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 meaning.


       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 example:

              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.


       Implicit coloring can be disabled by an empty file /etc/terminal-colors.d/sfdisk.disable.

       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.


              enables 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.


       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


       Karel Zak <>

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


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


       The  sfdisk  command  is  part  of  the  util-linux  package   and   is   available   from