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NAME | SYNOPSIS | DESCRIPTION | [PARTITION] SECTION OPTIONS | SPECIFIERS | EXAMPLES | SEE ALSO | NOTES | COLOPHON |
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REPART.D(5) repart.d REPART.D(5)
repart.d - Partition Definition Files for Automatic Boot-Time
Repartitioning
/etc/repart.d/*.conf
/run/repart.d/*.conf
/usr/lib/repart.d/*.conf
repart.d/*.conf files describe basic properties of partitions of
block devices of the local system. They may be used to declare
types, names and sizes of partitions that shall exist. The
systemd-repart(8) service reads these files and attempts to add
new partitions currently missing and enlarge existing partitions
according to these definitions. Operation is generally
incremental, i.e. when applied, what exists already is left
intact, and partitions are never shrunk, moved or deleted.
These definition files are useful for implementing operating
system images that are prepared and delivered with minimally
sized images (for example lacking any state or swap partitions),
and which on first boot automatically take possession of any
remaining disk space following a few basic rules.
Currently, support for partition definition files is only
implemented for GPT partitition tables.
Partition files are generally matched against any partitions
already existing on disk in a simple algorithm: the partition
files are sorted by their filename (ignoring the directory
prefix), and then compared in order against existing partitions
matching the same partition type UUID. Specifically, the first
existing partition with a specific partition type UUID is
assigned the first definition file with the same partition type
UUID, and the second existing partition with a specific type UUID
the second partition file with the same type UUID, and so on. Any
left-over partition files that have no matching existing
partition are assumed to define new partition that shall be
created. Such partitions are appended to the end of the partition
table, in the order defined by their names utilizing the first
partition slot greater than the highest slot number currently in
use. Any existing partitions that have no matching partition file
are left as they are.
Note that these definitions may only be used to created and
initialize new partitions or grow existing ones. In the latter
case it will not grow the contained files systems however;
separate mechanisms, such as systemd-growfs(8) may be used to
grow the file systems inside of these partitions.
Type=
The GPT partition type UUID to match. This may be a GPT
partition type UUID such as
4f68bce3-e8cd-4db1-96e7-fbcaf984b709, or one of the following
special identifiers:
Table 1. GPT partition type identifiers
┌──────────────────────┬──────────────────────────┐
│Identifier │ Explanation │
├──────────────────────┼──────────────────────────┤
│esp │ EFI System Partition │
├──────────────────────┼──────────────────────────┤
│xbootldr │ Extended Boot Loader │
│ │ Partition │
├──────────────────────┼──────────────────────────┤
│swap │ Swap partition │
├──────────────────────┼──────────────────────────┤
│home │ Home (/home/) partition │
├──────────────────────┼──────────────────────────┤
│srv │ Server data (/srv/) │
│ │ partition │
├──────────────────────┼──────────────────────────┤
│var │ Variable data (/var/) │
│ │ partition │
├──────────────────────┼──────────────────────────┤
│tmp │ Temporary data │
│ │ (/var/tmp/) partition │
├──────────────────────┼──────────────────────────┤
│linux-generic │ Generic Linux file │
│ │ system partition │
├──────────────────────┼──────────────────────────┤
│root │ Root file system │
│ │ partition type │
│ │ appropriate for the │
│ │ local architecture (an │
│ │ alias for an │
│ │ architecture root file │
│ │ system partition type │
│ │ listed below, e.g. │
│ │ root-x86-64) │
├──────────────────────┼──────────────────────────┤
│root-verity │ Verity data for the root │
│ │ file system partition │
│ │ for the local │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│root-secondary │ Root file system │
│ │ partition of the │
│ │ secondary architecture │
│ │ of the local │
│ │ architecture (usually │
│ │ the matching 32bit │
│ │ architecture for the │
│ │ local 64bit │
│ │ architecture) │
├──────────────────────┼──────────────────────────┤
│root-secondary-verity │ Verity data for the root │
│ │ file system partition of │
│ │ the secondary │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│root-x86 │ Root file system │
│ │ partition for the x86 │
│ │ (32bit, aka i386) │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│root-x86-verity │ Verity data for the x86 │
│ │ (32bit) root file system │
│ │ partition │
├──────────────────────┼──────────────────────────┤
│root-x86-64 │ Root file system │
│ │ partition for the x86_64 │
│ │ (64bit, aka amd64) │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│root-x86-64-verity │ Verity data for the │
│ │ x86_64 (64bit) root file │
│ │ system partition │
├──────────────────────┼──────────────────────────┤
│root-arm │ Root file system │
│ │ partition for the ARM │
│ │ (32bit) architecture │
├──────────────────────┼──────────────────────────┤
│root-arm-verity │ Verity data for the ARM │
│ │ (32bit) root file system │
│ │ partition │
├──────────────────────┼──────────────────────────┤
│root-arm64 │ Root file system │
│ │ partition for the ARM │
│ │ (64bit, aka aarch64) │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│root-arm64-verity │ Verity data for the ARM │
│ │ (64bit, aka aarch64) │
│ │ root file system │
│ │ partition │
├──────────────────────┼──────────────────────────┤
│root-ia64 │ Root file system │
│ │ partition for the ia64 │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│root-ia64-verity │ Verity data for the ia64 │
│ │ root file system │
│ │ partition │
├──────────────────────┼──────────────────────────┤
│root-riscv32 │ Root file system │
│ │ partition for the RISC-V │
│ │ 32-bit architecture │
├──────────────────────┼──────────────────────────┤
│root-riscv32-verity │ Verity data for the │
│ │ RISC-V 32-bit root file │
│ │ system partition │
├──────────────────────┼──────────────────────────┤
│root-riscv64 │ Root file system │
│ │ partition for the RISC-V │
│ │ 64-bit architecture │
├──────────────────────┼──────────────────────────┤
│root-riscv64-verity │ Verity data for the │
│ │ RISC-V 64-bit root file │
│ │ system partition │
├──────────────────────┼──────────────────────────┤
│usr │ /usr/ file system │
│ │ partition type │
│ │ appropriate for the │
│ │ local architecture (an │
│ │ alias for an │
│ │ architecture /usr/ file │
│ │ system partition type │
│ │ listed below, e.g. │
│ │ usr-x86-64) │
├──────────────────────┼──────────────────────────┤
│usr-verity │ Verity data for the │
│ │ /usr/ file system │
│ │ partition for the local │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│usr-secondary │ /usr/ file system │
│ │ partition of the │
│ │ secondary architecture │
│ │ of the local │
│ │ architecture (usually │
│ │ the matching 32bit │
│ │ architecture for the │
│ │ local 64bit │
│ │ architecture) │
├──────────────────────┼──────────────────────────┤
│usr-secondary-verity │ Verity data for the │
│ │ /usr/ file system │
│ │ partition of the │
│ │ secondary architecture │
├──────────────────────┼──────────────────────────┤
│usr-x86 │ /usr/ file system │
│ │ partition for the x86 │
│ │ (32bit, aka i386) │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│usr-x86-verity │ Verity data for the x86 │
│ │ (32bit) /usr/ file │
│ │ system partition │
├──────────────────────┼──────────────────────────┤
│usr-x86-64 │ /usr/ file system │
│ │ partition for the x86_64 │
│ │ (64bit, aka amd64) │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│usr-x86-64-verity │ Verity data for the │
│ │ x86_64 (64bit) /usr/ │
│ │ file system partition │
├──────────────────────┼──────────────────────────┤
│usr-arm │ /usr/ file system │
│ │ partition for the ARM │
│ │ (32bit) architecture │
├──────────────────────┼──────────────────────────┤
│usr-arm-verity │ Verity data for the ARM │
│ │ (32bit) /usr/ file │
│ │ system partition │
├──────────────────────┼──────────────────────────┤
│usr-arm64 │ /usr/ file system │
│ │ partition for the ARM │
│ │ (64bit, aka aarch64) │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│usr-arm64-verity │ Verity data for the ARM │
│ │ (64bit, aka aarch64) │
│ │ /usr/ file system │
│ │ partition │
├──────────────────────┼──────────────────────────┤
│usr-ia64 │ /usr/ file system │
│ │ partition for the ia64 │
│ │ architecture │
├──────────────────────┼──────────────────────────┤
│usr-ia64-verity │ Verity data for the ia64 │
│ │ /usr/ file system │
│ │ partition │
├──────────────────────┼──────────────────────────┤
│usr-riscv32 │ /usr/ file system │
│ │ partition for the RISC-V │
│ │ 32-bit architecture │
├──────────────────────┼──────────────────────────┤
│usr-riscv32-verity │ Verity data for the │
│ │ RISC-V 32-bit /usr/ file │
│ │ system partition │
├──────────────────────┼──────────────────────────┤
│usr-riscv64 │ /usr/ file system │
│ │ partition for the RISC-V │
│ │ 64-bit architecture │
├──────────────────────┼──────────────────────────┤
│usr-riscv64-verity │ Verity data for the │
│ │ RISC-V 64-bit /usr/ file │
│ │ system partition │
└──────────────────────┴──────────────────────────┘
This setting defaults to linux-generic.
Most of the partition type UUIDs listed above are defined in
the Discoverable Partitions Specification[1].
Label=
The textual label to assign to the partition if none is
assigned yet. Note that this setting is not used for
matching. It is also not used when a label is already set for
an existing partition. It is thus only used when a partition
is newly created or when an existing one had a no label set
(that is: an empty label). If not specified a label derived
from the partition type is automatically used. Simple
specifier expansion is supported, see below.
UUID=
The UUID to assign to the partition if none is assigned yet.
Note that this setting is not used for matching. It is also
not used when a UUID is already set for an existing
partition. It is thus only used when a partition is newly
created or when an existing one had a all-zero UUID set. If
not specified a UUID derived from the partition type is
automatically used.
Priority=
A numeric priority to assign to this partition, in the range
-2147483648...2147483647, with smaller values indicating
higher priority, and higher values indicating smaller
priority. This priority is used in case the configured size
constraints on the defined partitions do not permit fitting
all partitions onto the available disk space. If the
partitions do not fit, the highest numeric partition priority
of all defined partitions is determined, and all defined
partitions with this priority are removed from the list of
new partitions to create (which may be multiple, if the same
priority is used for multiple partitions). The fitting
algorithm is then tried again. If the partitions still do not
fit, the now highest numeric partition priority is
determined, and the matching partitions removed too, and so
on. Partitions of a priority of 0 or lower are never removed.
If all partitions with a priority above 0 are removed and the
partitions still do not fit on the device the operation
fails. Note that this priority has no effect on ordering
partitions, for that use the alphabetical order of the
filenames of the partition definition files. Defaults to 0.
Weight=
A numeric weight to assign to this partition in the range
0...1000000. Available disk space is assigned the defined
partitions according to their relative weights (subject to
the size constraints configured with SizeMinBytes=,
SizeMaxBytes=), so that a partition with weight 2000 gets
double the space as one with weight 1000, and a partition
with weight 333 a third of that. Defaults to 1000.
The Weight= setting is used to distribute available disk
space in an "elastic" fashion, based on the disk size and
existing partitions. If a partition shall have a fixed size
use both SizeMinBytes= and SizeMaxBytes= with the same value
in order to fixate the size to one value, in which case the
weight has no effect.
PaddingWeight=
Similar to Weight= but sets a weight for the free space after
the partition (the "padding"). When distributing available
space the weights of all partitions and all defined padding
is summed, and then each partition and padding gets the
fraction defined by its weight. Defaults to 0, i.e. by
default no padding is applied.
Padding is useful if empty space shall be left for later
additions or a safety margin at the end of the device or
between partitions.
SizeMinBytes=, SizeMaxBytes=
Specifies minimum and maximum size constraints in bytes.
Takes the usual K, M, G, T, ... suffixes (to the base of
1024). If SizeMinBytes= is specified the partition is created
at or grown to at least the specified size. If SizeMaxBytes=
is specified the partition is created at or grown to at most
the specified size. The precise size is determined through
the weight value value configured with Weight=, see above.
When SizeMinBytes= is set equal to SizeMaxBytes= the
configured weight has no effect as the partition is
explicitly sized to the specified fixed value. Note that
partitions are never created smaller than 4096 bytes, and
since partitions are never shrunk the previous size of the
partition (in case the partition already exists) is also
enforced as lower bound for the new size. The values should
be specified as multiples of 4096 bytes, and are rounded
upwards (in case of SizeMinBytes=) or downwards (in case of
SizeMaxBytes=) otherwise. If the backing device does not
provide enough space to fulfill the constraints placing the
partition will fail. For partitions that shall be created,
depending on the setting of Priority= (see above) the
partition might be dropped and the placing algorithm
restarted. By default a minimum size constraint of 10M and no
maximum size constraint is set.
PaddingMinBytes=, PaddingMaxBytes=
Specifies minimum and maximum size constraints in bytes for
the free space after the partition (the "padding"). Semantics
are similar to SizeMinBytes= and SizeMaxBytes=, except that
unlike partition sizes free space can be shrunk and can be as
small as zero. By default no size constraints on padding are
set, so that only PaddingWeight= determines the size of the
padding applied.
CopyBlocks=
Takes a path to a regular file, block device node or
directory. If specified and the partition is newly created
the data from the specified path is written to the newly
created partition, on the block level. If a directory is
specified the backing block device of the file system the
directory is on is determined and the data read directly from
that. This option is useful to efficiently replicate existing
file systems on the block level on a new partition, for
example to build a simple OS installer or OS image builder.
The file specified here must have a size that is a multiple
of the basic block size 512 and not be empty. If this option
is used, the size allocation algorithm is slightly altered:
the partition is created as least as big as required to fit
the data in, i.e. the data size is an additional minimum size
value taken into consideration for the allocation algorithm,
similar to and in addition to the SizeMin= value configured
above.
This option has no effect if the partition it is declared for
already exists, i.e. existing data is never overwritten. Note
that the data is copied in before the partition table is
updated, i.e. before the partition actually is persistently
created. This provides robustness: it is guaranteed that the
partition either doesn't exist or exists fully populated; it
is not possible that the partition exists but is not or only
partially populated.
This option cannot be combined with Format= or CopyFiles=.
Format=
Takes a file system name, such as "ext4", "btrfs", "xfs" or
"vfat", or the special value "swap". If specified and the
partition is newly created it is formatted with the specified
file system (or as swap device). The file system UUID and
label are automatically derived from the partition UUID and
label. If this option is used, the size allocation algorithm
is slightly altered: the partition is created as least as big
as required for the minimal file system of the specified type
(or 4KiB if the minimal size is not known).
This option has no effect if the partition already exists.
Similar to the behaviour of CopyBlocks= the file system is
formatted before the partition is created, ensuring that the
partition only ever exists with a fully initialized file
system.
This option cannot be combined with CopyBlocks=.
CopyFiles=
Takes a pair of colon separated absolute file system paths.
The first path refers to a source file or directory on the
host, the second path refers to a target in the file system
of the newly created partition and formatted file system.
This setting may be used to copy files or directories from
the host into the file system that is created due to the
Format= option. If CopyFiles= is used without Format=
specified explicitly, "Format=" with a suitable default is
implied (currently "ext4", but this may change in the
future). This option may be used multiple times to copy
multiple files or directories from host into the newly
formatted file system. The colon and second path may be
omitted in which case the source path is also used as the
target path (relative to the root of the newly created file
system). If the source path refers to a directory it is
copied recursively.
This option has no effect if the partition already exists: it
cannot be used to copy additional files into an existing
partition, it may only be used to populate a file system
created anew.
The copy operation is executed before the file system is
registered in the partition table, thus ensuring that a file
system populated this way only ever exists fully initialized.
This option cannot be combined with CopyBlocks=.
Encrypt=
Takes one of "off", "key-file", "tpm2" and "key-file+tpm2"
(alternatively, also accepts a boolean value, which is mapped
to "off" when false, and "key-file" when true). Defaults to
"off". If not "off" the partition will be formatted with a
LUKS2 superblock, before the blocks configured with
CopyBlocks= are copied in or the file system configured with
Format= is created.
The LUKS2 UUID is automatically derived from the partition
UUID in a stable fashion. If "key-file" or "key-file+tpm2" is
used a key is added to the LUKS2 superblock, configurable
with the --key-file= switch to systemd-repart. If "tpm2" or
"key-file+tpm2" is used a key is added to the LUKS2
superblock that is enrolled to the local TPM2 chip, as
configured with the --tpm2-device= and --tpm2-pcrs= options
to systemd-repart.
When used this slightly alters the size allocation logic as
the implicit, minimal size limits of Format= and CopyBlocks=
are increased by the space necessary for the LUKS2 superblock
(see above).
This option has no effect if the partition already exists.
FactoryReset=
Takes a boolean argument. If specified the partition is
marked for removal during a factory reset operation. This
functionality is useful to implement schemes where images can
be reset into their original state by removing partitions and
creating them anew. Defaults to off.
Specifiers may be used in the Label= setting. The following
expansions are understood:
Table 2. Specifiers available
┌──────────┬──────────────────┬────────────────────────┐
│Specifier │ Meaning │ Details │
├──────────┼──────────────────┼────────────────────────┤
│"%a" │ Architecture │ A short string │
│ │ │ identifying the │
│ │ │ architecture of │
│ │ │ the local system. │
│ │ │ A string such as │
│ │ │ x86, x86-64 or │
│ │ │ arm64. See the │
│ │ │ architectures │
│ │ │ defined for │
│ │ │ ConditionArchitecture= │
│ │ │ in systemd.unit(5) │
│ │ │ for a full list. │
├──────────┼──────────────────┼────────────────────────┤
│"%b" │ Boot ID │ The boot ID of the │
│ │ │ running system, │
│ │ │ formatted as string. │
│ │ │ See random(4) for more │
│ │ │ information. │
├──────────┼──────────────────┼────────────────────────┤
│"%B" │ Operating system │ The operating system │
│ │ build ID │ build identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ BUILD_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├──────────┼──────────────────┼────────────────────────┤
│"%H" │ Host name │ The hostname of the │
│ │ │ running system. │
├──────────┼──────────────────┼────────────────────────┤
│"%l" │ Short host name │ The hostname of the │
│ │ │ running system, │
│ │ │ truncated at the first │
│ │ │ dot to remove any │
│ │ │ domain component. │
├──────────┼──────────────────┼────────────────────────┤
│"%m" │ Machine ID │ The machine ID of the │
│ │ │ running system, │
│ │ │ formatted as string. │
│ │ │ See machine-id(5) for │
│ │ │ more information. │
├──────────┼──────────────────┼────────────────────────┤
│"%o" │ Operating system │ The operating system │
│ │ ID │ identifier of the │
│ │ │ running system, as │
│ │ │ read from the ID= │
│ │ │ field of │
│ │ │ /etc/os-release. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├──────────┼──────────────────┼────────────────────────┤
│"%v" │ Kernel release │ Identical to uname -r │
│ │ │ output. │
├──────────┼──────────────────┼────────────────────────┤
│"%w" │ Operating system │ The operating system │
│ │ version ID │ version identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ VERSION_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├──────────┼──────────────────┼────────────────────────┤
│"%W" │ Operating system │ The operating system │
│ │ variant ID │ variant identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ VARIANT_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├──────────┼──────────────────┼────────────────────────┤
│"%%" │ Single percent │ Use "%%" in place of │
│ │ sign │ "%" to specify a │
│ │ │ single percent sign. │
└──────────┴──────────────────┴────────────────────────┘
Example 1. Grow the root partition to the full disk size at first
boot
With the following file the root partition is automatically grown
to the full disk if possible during boot.
# /usr/lib/repart.d/50-root.conf
[Partition]
Type=root
Example 2. Create a swap and home partition automatically on
boot, if missing
The home partition gets all available disk space while the swap
partition gets 1G at most and 64M at least. We set a priority > 0
on the swap partition to ensure the swap partition is not used if
not enough space is available. For every three bytes assigned to
the home partition the swap partition gets assigned one.
# /usr/lib/repart.d/60-home.conf
[Partition]
Type=home
# /usr/lib/repart.d/70-swap.conf
[Partition]
Type=swap
SizeMinBytes=64M
SizeMaxBytes=1G
Priority=1
Weight=333
Example 3. Create B partitions in an A/B Verity setup, if missing
Let's say the vendor intends to update OS images in an A/B setup,
i.e. with two root partitions (and two matching Verity
partitions) that shall be used alternatingly during upgrades. To
minimize image sizes the original image is shipped only with one
root and one Verity partition (the "A" set), and the second root
and Verity partitions (the "B" set) shall be created on first
boot on the free space on the medium.
# /usr/lib/repart.d/50-root.conf
[Partition]
Type=root
SizeMinBytes=512M
SizeMaxBytes=512M
# /usr/lib/repart.d/60-root-verity.conf
[Partition]
Type=root-verity
SizeMinBytes=64M
SizeMaxBytes=64M
The definitions above cover the "A" set of root partition (of a
fixed 512M size) and Verity partition for the root partition (of
a fixed 64M size). Let's use symlinks to create the "B" set of
partitions, since after all they shall have the same properties
and sizes as the "A" set.
# ln -s 50-root.conf /usr/lib/repart.d/70-root-b.conf
# ln -s 60-root-verity.conf /usr/lib/repart.d/80-root-verity-b.conf
systemd(1), systemd-repart(8), sfdisk(8), systemd-cryptenroll(1)
1. Discoverable Partitions Specification
https://systemd.io/DISCOVERABLE_PARTITIONS
This page is part of the systemd (systemd system and service
manager) project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have
a bug report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
This page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2020-12-18. (At that
time, the date of the most recent commit that was found in the
repository was 2020-12-18.) If you discover any rendering
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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
man-pages@man7.org
systemd 247 REPART.D(5)
Pages that refer to this page: systemd.directives(7), systemd.index(7), systemd-repart(8)
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