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NAME | SYNOPSIS | DESCRIPTION | [PARTITION] SECTION OPTIONS | SPECIFIERS | ENVIRONMENT | 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/local/lib/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 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.
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.
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 │
└───────────────────────────┴──────────────────────────┘
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).
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.
If Format= is set, the minimum size is automatically raised to
the minimum file system size for the selected file system
type, if known. Moreover, for the ESP/XBOOTLDR partitions the
minimum is raised to 100M (for 512b sector images) or 260M
(for 4K sector images) automatically, if specified smaller.
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, char 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. Specify
/dev/urandom as value to initialize a partition with random
data.
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 at 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 does not 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 at least as big as required for the minimal file
system of the specified type (or 4KiB if the minimal size is
not known).
This also takes a special meta value "empty". If specified
this is equivalent to specifying "Label=_empty" and
"NoAuto=1".
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 colon-separated triplet in the form
"source[:target[:options]]". source is an absolute path which
refers to a source file or directory on the host. target is
an absolute path in the file system of the newly created
partition and formatted file system. options is a
comma-separated list of options where each option is in the
form "key[=value]".
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 target 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.
The options may contain the following values:
fsverity=
May be set to the value "off" (the default if the option
is not present) or "copy". If set to "off" then no files
copied into the filesystem from this source will have
fs-verity enabled. If set to "copy" then the fs-verity
information for each file will be copied from the
corresponding source file.
Added in version 258.
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 are not
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 one or more absolute paths, separated by whitespace,
each 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, it excludes 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.
MakeSymlinks=
Takes one or more arguments, separated by whitespace, each
declaring a symlink to create within the new file system. Each
argument is a pair of symlink source and target paths,
separated by a colon. This option may be used more than once
to create multiple symlinks. When CopyFiles= and MakeSymlinks=
are used together the former is applied first.
The primary use case for this option is to create symlinks
that need to exist before systemd-tmpfiles(8) is executed. For
example, when using systemd-confext(8), this setting can be
used to create symlinks in /var/lib/extensions.mutable to
redirect writes to mutable confexts to a custom location.
Consider using systemd-tmpfiles(8) with its --image= option to
pre-create other symlinks (as well as other inodes) with
fine-grained control of ownership, access modes and other file
attributes.
Added in version 257.
Subvolumes=
Takes one or more absolute paths, separated by whitespace,
each declaring a directory that should be a subvolume within
the new file system. Each path may optionally be followed by a
colon and a list of comma-separated subvolume flags. The
following flags are understood:
Table 2. Subvolume Flags
┌──────┬─────────────────────┐
│ Flag │ Purpose │
├──────┼─────────────────────┤
│ "ro" │ Make this subvolume │
│ │ read-only. │
└──────┴─────────────────────┘
Note that this option 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(8).
Note that this option is only supported in combination with
--offline=yes since btrfs-progs 6.12 or newer.
Added in version 255.
DefaultSubvolume=
Takes an absolute path specifying the default subvolume within
the new filesystem. Note that this setting does not create the
subvolume itself, that can be configured with Subvolumes=.
Note that this option only takes effect if the target
filesystem supports subvolumes, such as btrfs(8).
Note that this option is only supported in combination with
--offline=yes since btrfs-progs 6.12 or newer.
Added in version 256.
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 value 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 60 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.
MountPoint=
Specifies where and how the partition should be mounted. Takes
at least one and at most two fields separated with a colon
(":"). The first field specifies where the partition should be
mounted. The second field specifies extra mount options to
append to the default mount options. These fields correspond
to the second and fourth column of the fstab(5) format. This
setting may be specified multiple times to mount the partition
multiple times. This can be used to add mounts for different
btrfs(8) subvolumes located on the same btrfs partition.
Note that this setting is only taken into account when
--generate-fstab= is specified on the systemd-repart command
line.
Added in version 256.
EncryptedVolume=
Specifies how the encrypted partition should be set up. Takes
at least one and at most three fields separated with a colon
(":"). The first field specifies the encrypted volume name
under /dev/mapper/. If not specified, "luks-UUID" will be used
where "UUID" is the LUKS UUID. The second field specifies the
keyfile to use following the same format as specified in
crypttab. The third field specifies a comma-delimited list of
crypttab options. These fields correspond to the first, third
and fourth column of the crypttab(5) format.
Note that this setting is only taken into account when
--generate-crypttab= is specified on the systemd-repart
command line.
Added in version 256.
Compression=
Specifies the compression algorithm to use for the filesystem
configured with Format=. Takes a single argument specifying
the compression algorithm.
Note that this setting is only taken into account when the
filesystem configured with Format= supports compression (
btrfs(8), squashfs, erofs(5)). Here's an incomplete list of
compression algorithms supported by the filesystems known to
systemd-repart:
Table 3. File System Compression Algorithms
┌─────────────┬───────────────────┬───────────────┐
│ File System │ Compression │ Documentation │
│ │ Algorithms │ │
├─────────────┼───────────────────┼───────────────┤
│ squashfs │ gzip, lzo, lz4, │ mksquashfs(1) │
│ │ xz, zstd, lzma │ │
├─────────────┼───────────────────┼───────────────┤
│ erofs │ lz4, lz4hc, lzma, │ mkfs.erofs(1) │
│ │ deflate, │ │
│ │ libdeflate, zstd │ │
├─────────────┼───────────────────┼───────────────┤
│ btrfs │ zlib, lzo, zstd │ mkfs.btrfs(8) │
└─────────────┴───────────────────┴───────────────┘
Added in version 257.
CompressionLevel=
Specifies the compression level to use for the filesystem
configured with Format=. Takes a single argument specifying
the compression level to use for the configured compression
algorithm. The possible compression levels and their meaning
are filesystem specific (refer to the filesystem's
documentation for the exact meaning of a particular
compression level).
Note that this setting is only taken into account when the
filesystem configured with Format= supports compression and
the Compression= setting is configured explicitly.
Added in version 257.
SupplementFor=
Takes a partition definition name, such as "10-esp". If
specified, systemd-repart will avoid creating this partition
and instead prefer to partially merge the two definitions.
However, depending on the existing layout of partitions on
disk, systemd-repart may be forced to fall back onto
un-merging the definitions and using them as originally
written, potentially creating this partition. Specifically,
systemd-repart will fall back if this partition is found to
already exist on disk, or if the target partition already
exists on disk but is too small, or if it cannot allocate
space for the merged partition for some other reason.
The following fields are merged into the target definition in
the specified ways: Weight= and PaddingWeight= are simply
overwritten; SizeMinBytes= and PaddingMinBytes= use the larger
of the two values; SizeMaxBytes= and PaddingMaxBytes= use the
smaller value; and CopyFiles=, ExcludeFiles=,
ExcludeFilesTarget=, MakeDirectories=, and Subvolumes= are
concatenated.
Usage of this option in combination with CopyBlocks=,
Encrypt=, or Verity= is not supported. The target definition
cannot set these settings either. A definition cannot
simultaneously be a supplement and act as a target for some
other supplement definition. A target cannot have more than
one supplement partition associated with it.
For example, distributions can use this to implement $BOOT as
defined in the Boot Loader Specification[2]. Distributions may
prefer to use the ESP as $BOOT whenever possible, but to
adhere to the spec XBOOTLDR must sometimes be used instead.
So, they should create two definitions: the first defining an
ESP big enough to hold just the bootloader, and a second for
the XBOOTLDR that's sufficiently large to hold kernels and
configured as a supplement for the ESP. Whenever possible,
systemd-repart(8) will try to merge the two definitions to
create one large ESP, but if that's not allowable due to the
existing conditions on disk a small ESP and a large XBOOTLDR
will be created instead.
As another example, distributions can also use this to
seamlessly share a single /home partition in a multi-boot
scenario, while preferring to keep /home on the root partition
by default. Having a /home partition separated from the root
partition entails some extra complexity: someone has to decide
how to split the space between the two partitions. On the
other hand, it allows a user to share their home area between
multiple installed OSs (i.e. via systemd-homed.service(8)).
Distributions should create two definitions: the first for a
root partition that takes up some relatively small percentage
of the disk, and the second as a supplement for the first to
create a /home partition that takes up all the remaining free
space. On first boot, if systemd-repart finds an existing
/home partition on disk, it'll un-merge the definitions and
create just a small root partition. Otherwise, the definitions
will be merged and a single large root partition will be
created.
Added in version 257.
AddValidateFS=
Takes a boolean argument. If enabled will set the
user.validatefs.gpt_label, user.validatefs.gpt_type_uuid and
user.validatefs.mount_point extended attributes on the root
inode of the formatted file system to the partition labels,
partition type UUIDs and the intended mount point for the file
system. Defaults to on if Format= is used and the specified
argument is neither "swap" nor "vfat".
These extended attributes are read by
[email protected](8) and may encode constraints on
mounted file systems that must be fulfilled for the system to
successfully boot. This is particular important in
systemd-gpt-auto-generator(8) scenarios, which puts together
the mount hierarchy from untrusted data from the GPT partition
table. As these extended attributes are stored inside the file
system, they are typically authenticated as part of the file
system (assuming it is contained in protected volume; i.e.
LUKS or dm-verity), and hence may be used to securely validate
the matching partition table fields.
Added in version 258.
FileSystemSectorSize=
Controls the sector size for any file system, LUKS volume or
Verity volume formatted on this partition. Expects a power of
2 as value, and must be equal or larger than 512. Typically
it's recommended to set the file system sector size to 4096,
even on 512 sector disks (and in particular for images that
are only ever intended to be stored as file on disks), in
order to optimize performance. However, for compatibility with
foreign operating systems or firmware it might be advisable to
use the native sector size of the backing disk.
If unspecified and operating on a block device, defaults to
the native sector size of the device. If unspecified and
operating on a disk image file defaults to 4096.
Regardless of what is configured here, or which default is
picked, the file system sector size is always increased to be
equal or larger than the disk sector size.
Added in version 258.
Specifiers may be used in the Label=, CopyBlocks=, CopyFiles=,
MakeDirectories=, SplitName= settings. The following expansions
are understood:
Table 4. 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 │ 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. │
├───────────┼──────────────────┼────────────────────────┤
│ "%q" │ Pretty host name │ The pretty hostname of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ PRETTY_HOSTNAME= field │
│ │ │ of /etc/machine-info. │
│ │ │ If not set, resolves │
│ │ │ to the short hostname. │
│ │ │ See machine-info(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 │ Use "%%" in place of │
│ │ sign │ "%" to specify a │
│ │ │ single percent sign. │
└───────────┴──────────────────┴────────────────────────┘
Additionally, for the SplitName= setting, the following specifiers
are also understood:
Table 5. Specifiers available
┌───────────┬──────────────────┬────────────────────┐
│ Specifier │ Meaning │ Details │
├───────────┼──────────────────┼────────────────────┤
│ "%T" │ Partition Type │ The partition type │
│ │ UUID │ 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 │
└───────────┴──────────────────┴────────────────────┘
Extra filesystem formatting options can be provided using
filesystem-specific environment variables:
$SYSTEMD_REPART_MKFS_OPTIONS_BTRFS,
$SYSTEMD_REPART_MKFS_OPTIONS_XFS,
$SYSTEMD_REPART_MKFS_OPTIONS_VFAT,
$SYSTEMD_REPART_MKFS_OPTIONS_EROFS, and
$SYSTEMD_REPART_MKFS_OPTIONS_SQUASHFS. Each variable accepts valid
mkfs.filesystem command-line arguments. The content of those
variables is passed as-is to the command, without any
verification.
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
systemd(1), systemd-repart(8), sfdisk(8), systemd-cryptenroll(1)
1. Discoverable Partitions Specification
https://uapi-group.org/specifications/specs/discoverable_partitions_specification
2. Boot Loader Specification
https://uapi-group.org/specifications/specs/boot_loader_specification/
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 2025-08-11. (At that
time, the date of the most recent commit that was found in the
repository was 2025-08-11.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
systemd 258~rc2 REPART.D(5)
Pages that refer to this page: sysupdate.d(5), systemd.directives(7), systemd.index(7), systemd-repart(8)
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