Provided by: systemd_255.4-1ubuntu8.4_amd64 
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 partition
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
(32-bit), arm64 (64-bit, aka aarch64), ia64, loongarch64, mips-le, mips64-le, parisc,
ppc, ppc64, ppc64-le, riscv32, riscv64, s390, s390x, tilegx, x86 (32-bit, aka i386)
and x86-64 (64-bit, 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 32-bit architecture │
│ │ for the local 64-bit │
│ │ 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 32-bit architecture │
│ │ for the local 64-bit │
│ │ 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].
Added in version 245.
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.
Added in version 245.
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.
Added in version 246.
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.
Added in version 245.
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.
Added in version 245.
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.
Added in version 245.
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.
Added in version 245.
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.
Added in version 245.
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=.
Added in version 246.
Format=
Takes a file system name, such as "ext4", "btrfs", "xfs", "vfat", "erofs", "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=.
Added in version 247.
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 "vfat" for "ESP" and
"XBOOTLDR" partitions, and "ext4" otherwise, 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.
Note that CopyFiles= will skip copying files that aren't supported by the target
filesystem (e.g symlinks, fifos, sockets and devices on vfat). When an unsupported
file type is encountered, systemd-repart will skip copying this file and write a log
message about it.
Note that systemd-repart does not change the UIDs/GIDs of any copied files and
directories. When running systemd-repart as an unprivileged user to build an image of
files and directories owned by the same user, you can run systemd-repart in a user
namespace with the current user mapped to the root user to make sure the files and
directories in the image are owned by the root user.
Note that when populating XFS filesystems with systemd-repart and loop devices are not
available, populating XFS filesystems with files containing spaces, tabs or newlines
might fail on old versions of mkfs.xfs(8) due to limitations of its protofile format.
Note that when populating XFS filesystems with systemd-repart and loop devices are not
available, extended attributes will not be copied into generated XFS filesystems due
to limitations mkfs.xfs(8)'s protofile format.
This option cannot be combined with CopyBlocks=.
When systemd-repart(8) is invoked with the --copy-source= command line switch the file
paths are taken relative to the specified directory. If --copy-source= is not used,
but the --image= or --root= switches are used, the source paths are taken relative to
the specified root directory or disk image root.
Added in version 247.
ExcludeFiles=, ExcludeFilesTarget=
Takes an absolute file system path referring to a source file or directory on the
host. This setting may be used to exclude files or directories from the host from
being copied into the file system when CopyFiles= is used. This option may be used
multiple times to exclude multiple files or directories from host from being copied
into the newly formatted file system.
If the path is a directory and ends with "/", only the directory's contents are
excluded but not the directory itself. If the path is a directory and does not end
with "/", both the directory and its contents are excluded.
ExcludeFilesTarget= is like ExcludeFiles= except that instead of excluding the path on
the host from being copied into the partition, we exclude any files and directories
from being copied into the given path in the partition.
When systemd-repart(8) is invoked with the --image= or --root= command line switches
the paths specified are taken relative to the specified root directory or disk image
root.
Added in version 254.
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 use case 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.
Added in version 249.
Subvolumes=
Takes one or more absolute paths, separated by whitespace, each declaring a directory
that should be a subvolume within the new file system. This option may be used more
than once to specify multiple directories. Note that this setting does not create the
directories themselves, that can be configured with MakeDirectories= and CopyFiles=.
Note that this option only takes effect if the target filesystem supports subvolumes,
such as "btrfs".
Note that due to limitations of "mkfs.btrfs", this option is only supported when
running with --offline=no.
Added in version 255.
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.
Added in version 247.
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.
Added in version 252.
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=.
Added in version 252.
VerityDataBlockSizeBytes=
Configures the data block size of the generated verity hash partition. Must be between
512 and 4096 bytes and must be a power of 2. Defaults to the sector size if configured
explicitly, or the underlying block device sector size, or 4K if systemd-repart is not
operating on a block device.
Added in version 255.
VerityHashBlockSizeBytes=
Configures the hash block size of the generated verity hash partition. Must be between
512 and 4096 bytes and must be a power of 2. Defaults to the sector size if configured
explicitly, or the underlying block device sector size, or 4K if systemd-repart is not
operating on a block device.
Added in version 255.
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.
Added in version 245.
Flags=
Configures the 64-bit 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).
Added in version 249.
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).
Added in version 249.
SplitName=
Configures the suffix to append to split artifacts when the --split option of systemd-
repart(8) is used. Simple specifier expansion is supported, see below. Defaults to
"%t". To disable split artifact generation for a partition, set SplitName= to "-".
Added in version 252.
Minimize=
Takes one of "off", "best", and "guess" (alternatively, also accepts a boolean value,
which is mapped to "off" when false, and "best" when true). Defaults to "off". If set
to "best", the partition will have the minimal size required to store the sources
configured with CopyFiles=. "best" is currently only supported for read-only
filesystems. If set to "guess", the partition is created at least as big as required
to store the sources configured with CopyFiles=. Note that unless the filesystem is a
read-only filesystem, systemd-repart will have to populate the filesystem twice to
guess the minimal required size, so enabling this option might slow down repart when
populating large partitions.
Added in version 253.
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 image │ The operating system │
│ │ 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 build │ The operating system │
│ │ 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 image │ The operating system │
│ │ 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 version │ The operating system │
│ │ 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 variant │ The operating system │
│ │ 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 temporary │ This is either /tmp or │
│ │ files │ the path "$TMPDIR", │
│ │ │ "$TEMP" or "$TMP" are │
│ │ │ set to. (Note that the │
│ │ │ directory may be │
│ │ │ specified without a │
│ │ │ trailing slash.) │
├──────────┼──────────────────────────┼──────────────────────────┤
│"%V" │ Directory for larger and │ This is either /var/tmp │
│ │ persistent temporary │ or the path "$TMPDIR", │
│ │ files │ "$TEMP" or "$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 partition and corresponding verity partitions 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 matching verity partitions, we can do so as follows:
# 50-root.conf
[Partition]
Type=root
CopyFiles=/var/tmp/os-tree
Verity=data
VerityMatchKey=root
Minimize=guess
# 60-root-verity.conf
[Partition]
Type=root-verity
Verity=hash
VerityMatchKey=root
# Explicitly set the hash and data block size to 4K
VerityDataBlockSizeBytes=4096
VerityHashBlockSizeBytes=4096
Minimize=best
# 70-root-verity-sig.conf
[Partition]
Type=root-verity-sig
Verity=signature
VerityMatchKey=root
SEE ALSO
systemd(1), systemd-repart(8), sfdisk(8), systemd-cryptenroll(1)
NOTES
1. Discoverable Partitions Specification
https://uapi-group.org/specifications/specs/discoverable_partitions_specification