REPART.D(5) repart.d REPART.D(5)
NAME
repart.d - Partition Definition Files for Automatic Boot-Time
Repartitioning
SYNOPSIS
/etc/repart.d/*.conf
/run/repart.d/*.conf
/usr/lib/repart.d/*.conf
DESCRIPTION
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 create and initialize
new partitions or to 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. Partitions may also be marked for automatic growing via the
GrowFileSystem= setting, in which case the file system is grown on
first mount by tools that respect this flag. See below for details.
[PARTITION] SECTION OPTIONS
Type=
The GPT partition type UUID to match. This may be a GPT partition
type UUID such as 4f68bce3-e8cd-4db1-96e7-fbcaf984b709, or an
identifier. Architecture specific partition types can use one of
these architecture identifiers: alpha, arc, arm (32bit), arm64
(64bit, aka aarch64), ia64, loongarch64, mips-le, mips64-le,
parisc, ppc, ppc64, ppc64-le, riscv32, riscv64, s390, s390x,
tilegx, x86 (32bit, aka i386) and x86-64 (64bit, aka amd64). The
supported identifiers are:
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-verity-sig │ Verity signature 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-secondary-verity-sig │ Verity signature data for │
│ │ the root file system │
│ │ partition of the secondary │
│ │ architecture │
├──────────────────────────┼────────────────────────────┤
│root-{arch} │ Root file system partition │
│ │ of the given architecture │
│ │ (such as root-x86-64 or │
│ │ root-riscv64) │
├──────────────────────────┼────────────────────────────┤
│root-{arch}-verity │ Verity data for the root │
│ │ file system partition of │
│ │ the given architecture │
├──────────────────────────┼────────────────────────────┤
│root-{arch}-verity-sig │ Verity signature data for │
│ │ the root file system │
│ │ partition of the given │
│ │ architecture │
├──────────────────────────┼────────────────────────────┤
│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-verity-sig │ Verity signature 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-secondary-verity-sig │ Verity signature data for │
│ │ the /usr/ file system │
│ │ partition of the secondary │
│ │ architecture │
├──────────────────────────┼────────────────────────────┤
│usr-{arch} │ /usr/ file system │
│ │ partition of the given │
│ │ architecture │
├──────────────────────────┼────────────────────────────┤
│usr-{arch}-verity │ Verity data for the /usr/ │
│ │ file system partition of │
│ │ the given architecture │
├──────────────────────────┼────────────────────────────┤
│usr-{arch}-verity-sig │ Verity signature data for │
│ │ the /usr/ file system │
│ │ partition of the given │
│ │ architecture │
└──────────────────────────┴────────────────────────────┘
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 set to "null", the UUID is set to all
zeroes. 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 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, or
the special value "auto". 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 onto new
partitions on the block level — for example to build a simple OS
installer or an OS image builder.
If the special value "auto" is specified, the source to copy from
is automatically picked up from the running system (or the image
specified with --image= — if used). A partition that matches both
the configured partition type (as declared with Type= described
above), and the currently mounted directory appropriate for that
partition type is determined. For example, if the partition type is
set to "root" the partition backing the root directory (/) is used
as source to copy from — if its partition type is set to "root" as
well. If the declared type is "usr" the partition backing /usr/ is
used as source to copy blocks from — if its partition type is set
to "usr" too. The logic is capable of automatically tracking down
the backing partitions for encrypted and Verity-enabled volumes.
"CopyBlocks=auto" is useful for implementing "self-replicating"
systems, i.e. systems that are their own installer.
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", "vfat",
"squashfs", 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.
Similarly 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=.
When systemd-repart is invoked with the --image= or --root= command
line switches the source paths specified are taken relative to the
specified root directory or disk image root.
MakeDirectories=
Takes one or more absolute paths, separated by whitespace, each
declaring a directory to create within the new file system.
Behaviour is similar to CopyFiles=, but instead of copying in a set
of files this just creates the specified directories with the
default mode of 0755 owned by the root user and group, plus all
their parent directories (with the same ownership and access mode).
To configure directories with different ownership or access mode,
use CopyFiles= and specify a source tree to copy containing
appropriately owned/configured directories. This option may be used
more than once to create multiple directories. When CopyFiles= and
MakeDirectories= are used together the former is applied first. If
a directory listed already exists no operation is executed (in
particular, the ownership/access mode of the directories is left as
is).
The primary usecase for this option is to create a minimal set of
directories that may be mounted over by other partitions contained
in the same disk image. For example, a disk image where the root
file system is formatted at first boot might want to automatically
pre-create /usr/ in it this way, so that the "usr" partition may
over-mount it.
Consider using systemd-tmpfiles(8) with its --image= option to
pre-create other, more complex directory hierarchies (as well as
other inodes) with fine-grained control of ownership, access modes
and other file attributes.
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=
option 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.
Verity=
Takes one of "off", "data", "hash" or "signature". Defaults to
"off". If set to "off" or "data", the partition is populated with
content as specified by CopyBlocks= or CopyFiles=. If set to
"hash", the partition will be populated with verity hashes from the
matching verity data partition. If set to "signature", The
partition will be populated with a JSON object containing a
signature of the verity root hash of the matching verity hash
partition.
A matching verity partition is a partition with the same verity
match key (as configured with VerityMatchKey=).
If not explicitly configured, the data partition's UUID will be set
to the first 128 bits of the verity root hash. Similarly, if not
configured, the hash partition's UUID will be set to the final 128
bits of the verity root hash. The verity root hash itself will be
included in the output of systemd-repart.
This option has no effect if the partition already exists.
Usage of this option in combination with Encrypt= is not supported.
For each unique VerityMatchKey= value, a single verity data
partition ("Verity=data") and a single verity hash partition
("Verity=hash") must be defined.
VerityMatchKey=
Takes a short, user-chosen identifier string. This setting is used
to find sibling verity partitions for the current verity partition.
See the description for Verity=.
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.
Flags=
Configures the 64bit GPT partition flags field to set for the
partition when creating it. This option has no effect if the
partition already exists. If not specified the flags values is set
to all zeroes, except for the three bits that can also be
configured via NoAuto=, ReadOnly= and GrowFileSystem=; see below
for details on the defaults for these three flags. Specify the
flags value in hexadecimal (by prefixing it with "0x"), binary
(prefix "0b") or decimal (no prefix).
NoAuto=, ReadOnly=, GrowFileSystem=
Configures the No-Auto, Read-Only and Grow-File-System partition
flags (bit 63, 60 and 59) of the partition table entry, as defined
by the Discoverable Partitions Specification[1]. Only available for
partition types supported by the specification. This option is a
friendly way to set bits 63, 60 and 59 of the partition flags value
without setting any of the other bits, and may be set via Flags=
too, see above.
If Flags= is used in conjunction with one or more of
NoAuto=/ReadOnly=/GrowFileSystem= the latter control the value of
the relevant flags, i.e. the high-level settings
NoAuto=/ReadOnly=/GrowFileSystem= override the relevant bits of the
low-level setting Flags=.
Note that the three flags affect only automatic partition mounting,
as implemented by systemd-gpt-auto-generator(8) or the --image=
option of various commands (such as systemd-nspawn(1)). It has no
effect on explicit mounts, such as those done via mount(8) or
fstab(5).
If both bit 50 and 59 are set for a partition (i.e. the partition
is marked both read-only and marked for file system growing) the
latter is typically without effect: the read-only flag takes
precedence in most tools reading these flags, and since growing the
file system involves writing to the partition it is consequently
ignored.
NoAuto= defaults to off. ReadOnly= defaults to on for Verity
partition types, and off for all others. GrowFileSystem= defaults
to on for all partition types that support it, except if the
partition is marked read-only (and thus effectively, defaults to
off for Verity partitions).
SplitName=
Configures the suffix to append to split artifacts when the --split
option of systemd-repart is used. Simple specifier expansion is
supported, see below. Defaults to "%t". To disable split artifact
generation for a partition, set SplitName= to "-".
SPECIFIERS
Specifiers may be used in the Label=, CopyBlocks=, CopyFiles=,
MakeDirectories=, SplitName= settings. 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. │
├──────────┼─────────────────────┼────────────────────────┤
│"%A" │ Operating system │ The operating system │
│ │ image version │ image version │
│ │ │ identifier of the │
│ │ │ running system, as │
│ │ │ read from the │
│ │ │ IMAGE_VERSION= field │
│ │ │ of /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├──────────┼─────────────────────┼────────────────────────┤
│"%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. │
├──────────┼─────────────────────┼────────────────────────┤
│"%M" │ Operating system │ The operating system │
│ │ image identifier │ image identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ IMAGE_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├──────────┼─────────────────────┼────────────────────────┤
│"%o" │ Operating system ID │ The operating system │
│ │ │ 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. │
├──────────┼─────────────────────┼────────────────────────┤
│"%T" │ Directory for │ This is either /tmp or │
│ │ temporary files │ the path "$TMPDIR", │
│ │ │ "$TEMP" or "$TMP" are │
│ │ │ set to. (Note that the │
│ │ │ directory may be │
│ │ │ specified without a │
│ │ │ trailing slash.) │
├──────────┼─────────────────────┼────────────────────────┤
│"%V" │ Directory for │ This is either │
│ │ larger and │ /var/tmp or the path │
│ │ persistent │ "$TMPDIR", "$TEMP" or │
│ │ temporary files │ "$TMP" are set to. │
│ │ │ (Note that the │
│ │ │ directory may be │
│ │ │ specified without a │
│ │ │ trailing slash.) │
├──────────┼─────────────────────┼────────────────────────┤
│"%%" │ Single percent sign │ Use "%%" in place of │
│ │ │ "%" to specify a │
│ │ │ single percent sign. │
└──────────┴─────────────────────┴────────────────────────┘
Additionally, for the SplitName= setting, the following specifiers are
also understood:
Table 3. Specifiers available
┌──────────┬─────────────────────┬─────────────────────┐
│Specifier │ Meaning │ Details │
├──────────┼─────────────────────┼─────────────────────┤
│"%T" │ Partition Type UUID │ The partition type │
│ │ │ UUID, as configured │
│ │ │ with Type= │
├──────────┼─────────────────────┼─────────────────────┤
│"%t" │ Partition Type │ The partition type │
│ │ Identifier │ identifier │
│ │ │ corresponding to │
│ │ │ the partition type │
│ │ │ UUID │
├──────────┼─────────────────────┼─────────────────────┤
│"%U" │ Partition UUID │ The partition UUID, │
│ │ │ as configured with │
│ │ │ UUID= │
├──────────┼─────────────────────┼─────────────────────┤
│"%n" │ Partition Number │ The partition │
│ │ │ number assigned to │
│ │ │ the partition │
└──────────┴─────────────────────┴─────────────────────┘
EXAMPLES
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
Example 4. Create a data and verity partition from a OS tree
Assuming we have an OS tree at /var/tmp/os-tree that we want to package
in a root partition together with a matching verity partition, we can
do so as follows:
# 50-root.conf
[Partition]
Type=root
CopyFiles=/var/tmp/os-tree
Verity=data
VerityMatchKey=root
# 60-root-verity.conf
[Partition]
Type=root-verity
Verity=hash
VerityMatchKey=root
SEE ALSO
systemd(1), systemd-repart(8), sfdisk(8), systemd-cryptenroll(1)
NOTES
1. Discoverable Partitions Specification
https://systemd.io/DISCOVERABLE_PARTITIONS
systemd 252 REPART.D(5)
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