Section: System Administration (8)
Updated: June 2015
sfdisk - display or manipulate a disk partition table
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
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.
(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
does not create the standard system partitions for SGI and SUN disk labels like
It is necessary to explicitly create all partitions including whole-disk system
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
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 partitions.
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
- --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 are:
- 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
- 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
- --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
- -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
- -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., 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
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
- -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.
- -v, --version
Display version information and exit.
- -h, --help
Display help text and exit.
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:
Specify the partitioning unit. The only supported unit is sectors.
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.
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 ignored.
Note that it is only possible to use header lines before the first partition
is specified in the input.
where each line fills one partition descriptor.
start size type bootable
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
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
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.
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
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 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 GPT
The shortcut 'X' for Linux extended partition (85) is deprecated in favour of 'Ex'.
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.
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
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.
[device :] name[=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 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.
EMPTY DISK LABEL
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.
BACKING UP THE PARTITION TABLE
It is recommended to save the layout of your devices.
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.
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
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
provides all necessary functionality.
Implicit coloring can be disabled by an empty file /etc/terminal-colors.d/sfdisk.disable
for more details about colorization configuration. The logical color names
The header of the output tables.
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
option to force the kernel to reread the partition table.
Use blockdev --rereadpt
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.
Karel Zak <email@example.com
The current sfdisk implementation is based on the original sfdisk
from Andries E. Brouwer.
The sfdisk command is part of the util-linux package and is available from