sfdisk is a script-oriented tool for partitioning any block device.
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
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
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.
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
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. 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 PARTITIONTABLE.
-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, or a GUID for GPT. For backward
compatibility the options -c and --id have the same meaning as
--part-uuid device partition-number [uuid]
Change the GPT partition UUID. If uuid is not specified, then
print the current partition UUID.
-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.
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.
Don't create a new partition table, but only append the
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
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.
Disable all consistency checking.
Deprecated and ignored option. Partitioning that is
compatible with Linux (and other modern operating systems) is
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 path overrides the default log file name (the default is
~/sfdisk-<devname>.move). The log file contains information
about all read/write operations on the partition data.
Note that this operation is risky and not atomic. Don't forgetto backup your data!
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 1echo '2048,' | sfdisk /dev/sdc --appendsfdisk /dev/sdc --reorder-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).
Suppress extra info messages.
-u, --unit S
Deprecated option. Only the sector unit is supported.
-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 to edit 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)
-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.
Display version information and exit.
Display help text and exit.
sfdisk supports two input formats and generic header lines.
The optional header lines specify generic information that
apply to the partition table. The header-line format is:
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.
Note that it is only possible to use header lines before the
first partition is specified in the input.
Unnamed-fields formatstart 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), without the
0x prefix, a GUID string for GPT, or a shortcut:
L Linux; means 83 for MBR and
0FC63DAF-8483-4772-8E79-3D69D8477DE4 for GPT.
S swap area; means 82 for MBR and 0657FD6D-
A4AB-43C4-84E5-0933C84B4F4F for GPT
E extended partition; means 5 for MBR
H home partition; means
933AC7E1-2EB4-4F13-B844-0E14E2AEF915 for GPT
X linux extended partition; means 85 for MBR.
U EFI System partition, means EF for MBR and
C12A7328-F81F-11D2-BA4B-00A0C93EC93B for GPT
The default type value is Lbootable 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 ir might play a role for
certain boot loaders and for other operating systems.
This format is more readable, robust, extensible and allows to
specify additional information (e.g. a UUID). It is
recommended to use this format to keep your scripts more
[device:] name[=value], ...
The device field is optional. sfdisk extracts the partition
number from the device name. It allows to specify 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
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, or a GUID for a GPT partition. For
backward compatibility the Id= field has the
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
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.
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.
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.
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
firstname.lastname@example.org. This page was obtained from the
project's upstream Git repository
2017-03-13. If you discover any rendering problems in this HTML ver‐
sion 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 man‐
ual page), send a mail to email@example.com
util-linux June 2015 SFDISK(8)