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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXIT STATUS | EXAMPLE | SEE ALSO | NOTES | COLOPHON |
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SYSTEMD-REPART(8) systemd-repart SYSTEMD-REPART(8)
systemd-repart, systemd-repart.service - Automatically grow and
add partitions
systemd-repart [OPTIONS...] [[BLOCKDEVICE]...]
systemd-repart.service
systemd-repart grows and adds partitions to a partition table,
based on the configuration files described in repart.d(5).
If invoked with no arguments, it operates on the block device
backing the root file system partition of the running OS, thus
growing and adding partitions of the booted OS image itself. If
--image= is used it will operate on the specified image file.
When called in the initrd it operates on the block device backing
/sysroot/ instead, i.e. on the block device the system will soon
transition into. The systemd-repart.service service is generally
run at boot in the initrd, in order to augment the partition
table of the OS before its partitions are mounted.
systemd-repart (mostly) operates in a purely incremental mode: it
only grows existing and adds new partitions; it does not shrink,
delete or move existing partitions. The service is intended to be
run on every boot, but when it detects that the partition table
already matches the installed repart.d/*.conf configuration
files, it executes no operation.
systemd-repart is intended to be used when deploying OS images,
to automatically adjust them to the system they are running on,
during first boot. This way the deployed image can be minimal in
size and may be augmented automatically at boot when needed,
taking possession of disk space available but not yet used.
Specifically the following use cases are among those covered:
• The root partition may be grown to cover the whole available
disk space.
• A /home/, swap or /srv/ partition can be added.
• A second (or third, ...) root partition may be added, to
cover A/B style setups where a second version of the root
file system is alternatingly used for implementing update
schemes. The deployed image would carry only a single
partition ("A") but on first boot a second partition ("B")
for this purpose is automatically created.
The algorithm executed by systemd-repart is roughly as follows:
1. The repart.d/*.conf configuration files are loaded and
parsed, and ordered by filename (without the directory
prefix). For each configuration file, drop-in files are
looked for in directories with same name as the configuration
file with a suffix ".d" added.
2. The partition table already existing on the block device is
loaded and parsed.
3. The existing partitions in the partition table are matched up
with the repart.d/*.conf files by GPT partition type UUID.
The first existing partition of a specific type is assigned
the first configuration file declaring the same type. The
second existing partition of a specific type is then assigned
the second configuration file declaring the same type, and so
on. After this iterative assigning is complete any left-over
existing partitions that have no matching configuration file
are considered "foreign" and left as they are. And any
configuration files for which no partition currently exists
are understood as a request to create such a partition.
4. Partitions that shall be created are now allocated on the
disk, taking the size constraints and weights declared in the
configuration files into account. Free space is used within
the limits set by size and padding requests. In addition,
existing partitions that should be grown are grown. New
partitions are always appended to the end of the partition
table, taking the first partition table slot whose index is
greater than the indexes of all existing partitions.
Partitions are never reordered and thus partition numbers
remain stable. When partitions are created, they are placed
in the smallest area of free space that is large enough to
satisfy the size and padding limits. This means that
partitions might have different order on disk than in the
partition table. Note that this allocation happens in memory
only, the partition table on disk is not updated yet.
5. All existing partitions for which configuration files exist
and which currently have no GPT partition label set will be
assigned a label, either explicitly configured in the
configuration or — if that's missing — derived automatically
from the partition type. The same is done for all partitions
that are newly created. These assignments are done in memory
only, too, the disk is not updated yet.
6. Similarly, all existing partitions for which configuration
files exist and which currently have an all-zero identifying
UUID will be assigned a new UUID. This UUID is
cryptographically hashed from a common seed value together
with the partition type UUID (and a counter in case multiple
partitions of the same type are defined), see below. The same
is done for all partitions that are created anew. These
assignments are done in memory only, too, the disk is not
updated yet.
7. Similarly, if the disk's volume UUID is all zeroes it is also
initialized, also cryptographically hashed from the same
common seed value. This is done in memory only too.
8. The disk space assigned to new partitions (i.e. what was
previously free space) is now erased. Specifically, all file
system signatures are removed, and if the device supports it,
the BLKDISCARD I/O control command is issued to inform the
hardware that the space is now empty. In addition any
"padding" between partitions and at the end of the device is
similarly erased.
9. The new partition table is finally written to disk. The
kernel is asked to reread the partition table.
As exception to the normally strictly incremental operation, when
called in a special "factory reset" mode, systemd-repart may also
be used to erase existing partitions to reset an installation
back to vendor defaults. This mode of operation is used when
either the --factory-reset=yes switch is passed on the tool's
command line, or the systemd.factory_reset=yes option specified
on the kernel command line, or the FactoryReset EFI variable
(vendor UUID 8cf2644b-4b0b-428f-9387-6d876050dc67) is set to
"yes". It alters the algorithm above slightly: between the 3rd
and the 4th step above any partition marked explicitly via the
FactoryReset= boolean is deleted, and the algorithm restarted,
thus immediately re-creating these partitions anew empty.
Note that systemd-repart by default only changes partition
tables, it does not create or resize any file systems within
these partitions, unless the Format= configuration option is
specified. Also note that there are also separate mechanisms
available for this purpose, for example systemd-growfs(8) and
systemd-makefs.
The UUIDs identifying the new partitions created (or assigned to
existing partitions that have no UUID yet), as well as the disk
as a whole are hashed cryptographically from a common seed value.
This seed value is usually the machine-id(5) of the system, so
that the machine ID reproducibly determines the UUIDs assigned to
all partitions. If the machine ID cannot be read (or the user
passes --seed=random, see below) the seed is generated randomly
instead, so that the partition UUIDs are also effectively random.
The seed value may also be set explicitly, formatted as UUID via
the --seed= option. By hashing these UUIDs from a common seed
images prepared with this tool become reproducible and the result
of the algorithm above deterministic.
The positional argument should specify the block device to
operate on. Instead of a block device node path a regular file
may be specified too, in which case the command operates on it
like it would if a loopback block device node was specified with
the file attached. If --empty=create is specified the specified
path is created as regular file, which is useful for generating
disk images from scratch.
The following options are understood:
--dry-run=
Takes a boolean. If this switch is not specified
--dry-run=yes is the implied default. Controls whether
systemd-repart executes the requested re-partition operations
or whether it should only show what it would do. Unless
--dry-run=no is specified systemd-repart will not actually
touch the device's partition table.
Added in version 245.
--empty=
Takes one of "refuse", "allow", "require", "force" or
"create". Controls how to operate on block devices that are
entirely empty, i.e. carry no partition table/disk label yet.
If this switch is not specified the implied default is
"refuse".
If "refuse" systemd-repart requires that the block device it
shall operate on already carries a partition table and
refuses operation if none is found. If "allow" the command
will extend an existing partition table or create a new one
if none exists. If "require" the command will create a new
partition table if none exists so far, and refuse operation
if one already exists. If "force" it will create a fresh
partition table unconditionally, erasing the disk fully in
effect. If "force" no existing partitions will be taken into
account or survive the operation. Hence: use with care, this
is a great way to lose all your data. If "create" a new
loopback file is create under the path passed via the device
node parameter, of the size indicated with --size=, see
below.
Added in version 245.
--discard=
Takes a boolean. If this switch is not specified
--discard=yes is the implied default. Controls whether to
issue the BLKDISCARD I/O control command on the space taken
up by any added partitions or on the space in between them.
Usually, it's a good idea to issue this request since it
tells the underlying hardware that the covered blocks shall
be considered empty, improving performance. If operating on a
regular file instead of a block device node, a sparse file is
generated.
Added in version 245.
--size=
Takes a size in bytes, using the usual K, M, G, T suffixes,
or the special value "auto". If used the specified device
node path must refer to a regular file, which is then grown
to the specified size if smaller, before any change is made
to the partition table. If specified as "auto" the minimal
size for the disk image is automatically determined (i.e. the
minimal sizes of all partitions are summed up, taking space
for additional metadata into account). This switch is not
supported if the specified node is a block device. This
switch has no effect if the file is already as large as the
specified size or larger. The specified size is implicitly
rounded up to multiples of 4096. When used with
--empty=create this specifies the initial size of the
loopback file to create.
The --size=auto option takes the sizes of pre-existing
partitions into account. However, it does not accommodate for
partition tables that are not tightly packed: the configured
partitions might still not fit into the backing device if
empty space exists between pre-existing partitions (or before
the first partition) that cannot be fully filled by
partitions to grow or create.
Also note that the automatic size determination does not take
files or directories specified with CopyFiles= into account:
operation might fail if the specified files or directories
require more disk space then the configured per-partition
minimal size limit.
Added in version 246.
--factory-reset=
Takes boolean. If this switch is not specified
--factory=reset=no is the implied default. Controls whether
to operate in "factory reset" mode, see above. If set to true
this will remove all existing partitions marked with
FactoryReset= set to yes early while executing the
re-partitioning algorithm. Use with care, this is a great way
to lose all your data. Note that partition files need to
explicitly turn FactoryReset= on, as the option defaults to
off. If no partitions are marked for factory reset this
switch has no effect. Note that there are two other methods
to request factory reset operation: via the kernel command
line and via an EFI variable, see above.
Added in version 245.
--can-factory-reset
If this switch is specified the disk is not re-partitioned.
Instead it is determined if any existing partitions are
marked with FactoryReset=. If there are the tool will exit
with exit status zero, otherwise non-zero. This switch may be
used to quickly determine whether the running system supports
a factory reset mechanism built on systemd-repart.
Added in version 245.
--root=
Takes a path to a directory to use as root file system when
searching for repart.d/*.conf files, for the machine ID file
to use as seed and for the CopyFiles= and CopyBlocks= source
files and directories. By default when invoked on the regular
system this defaults to the host's root file system /. If
invoked from the initrd this defaults to /sysroot/, so that
the tool operates on the configuration and machine ID stored
in the root file system later transitioned into itself.
See --copy-source= for a more restricted option that only
affects CopyFiles=.
Added in version 245.
--image=
Takes a path to a disk image file or device to mount and use
in a similar fashion to --root=, see above.
Added in version 249.
--image-policy=policy
Takes an image policy string as argument, as per
systemd.image-policy(7). The policy is enforced when
operating on the disk image specified via --image=, see
above. If not specified defaults to the "*" policy, i.e. all
recognized file systems in the image are used.
--seed=
Takes a UUID as argument or the special value random. If a
UUID is specified the UUIDs to assign to partitions and the
partition table itself are derived via cryptographic hashing
from it. If not specified it is attempted to read the machine
ID from the host (or more precisely, the root directory
configured via --root=) and use it as seed instead, falling
back to a randomized seed otherwise. Use --seed=random to
force a randomized seed. Explicitly specifying the seed may
be used to generated strictly reproducible partition tables.
Added in version 245.
--pretty=
Takes a boolean argument. If this switch is not specified, it
defaults to on when called from an interactive terminal and
off otherwise. Controls whether to show a user friendly table
and graphic illustrating the changes applied.
Added in version 245.
--definitions=
Takes a file system path. If specified the *.conf files are
read from the specified directory instead of searching in
/usr/lib/repart.d/*.conf, /etc/repart.d/*.conf,
/run/repart.d/*.conf.
This parameter can be specified multiple times.
Added in version 245.
--key-file=
Takes a file system path. Configures the encryption key to
use when setting up LUKS2 volumes configured with the
Encrypt=key-file setting in partition files. Should refer to
a regular file containing the key, or an AF_UNIX stream
socket in the file system. In the latter case a connection is
made to it and the key read from it. If this switch is not
specified the empty key (i.e. zero length key) is used. This
behaviour is useful for setting up encrypted partitions
during early first boot that receive their user-supplied
password only in a later setup step.
Added in version 247.
--private-key=
Takes a file system path. Configures the signing key to use
when creating verity signature partitions with the
Verity=signature setting in partition files.
Added in version 252.
--private-key-source=
Takes one of "file", "engine" or "provider". In the latter
two cases, it is followed by the name of a provider or
engine, separated by colon, that will be passed to OpenSSL's
"engine" or "provider" logic. Configures the signing
mechanism to use when creating verity signature partitions
with the Verity=signature setting in partition files.
Added in version 256.
--certificate=
Takes a file system path. Configures the PEM encoded X.509
certificate to use when creating verity signature partitions
with the Verity=signature setting in partition files.
Added in version 252.
--tpm2-device=, --tpm2-pcrs=
Configures the TPM2 device and list of PCRs to use for LUKS2
volumes configured with the Encrypt=tpm2 option. These
options take the same parameters as the identically named
options to systemd-cryptenroll(1) and have the same effect on
partitions where TPM2 enrollment is requested.
Added in version 248.
--tpm2-device-key=PATH, --tpm2-seal-key-handle=HANDLE
Configures a TPM2 SRK key to bind encryption to. See
systemd-cryptenroll(1) for details on this option.
Added in version 255.
--tpm2-public-key=PATH, --tpm2-public-key-pcrs=PCR[+PCR...]
Configures a TPM2 signed PCR policy to bind encryption to.
See systemd-cryptenroll(1) for details on these two options.
Added in version 252.
--tpm2-pcrlock=PATH
Configures a TPM2 pcrlock policy to bind encryption to. See
systemd-cryptenroll(1) for details on this option.
Added in version 255.
--split=BOOL
Enables generation of split artifacts from partitions
configured with SplitName=. If enabled, for each partition
with SplitName= set, a separate output file containing just
the contents of that partition is generated. The output
filename consists of the loopback filename suffixed with the
name configured with SplitName=. If the loopback filename
ends with ".raw", the suffix is inserted before the ".raw"
extension instead.
Note that --split is independent from --dry-run. Even if
--dry-run is enabled, split artifacts will still be generated
from an existing image if --split is enabled.
Added in version 252.
--include-partitions=PARTITIONS, --exclude-partitions=PARTITIONS
These options specify which partition types systemd-repart
should operate on. If --include-partitions= is used, all
partitions that aren't specified are excluded. If
--exclude-partitions= is used, all partitions that are
specified are excluded. Both options take a comma separated
list of GPT partition type UUIDs or identifiers (see Type= in
repart.d(5)).
Added in version 253.
--defer-partitions=PARTITIONS
This option specifies for which partition types
systemd-repart should defer. All partitions that are deferred
using this option are still taken into account when
calculating the sizes and offsets of other partitions, but
aren't actually written to the disk image. The net effect of
this option is that if you run systemd-repart again without
this option, the missing partitions will be added as if they
had not been deferred the first time systemd-repart was
executed.
Added in version 253.
--sector-size=BYTES
This option allows configuring the sector size of the image
produced by systemd-repart. It takes a value that is a power
of "2" between "512" and "4096". This option is useful when
building images for disks that use a different sector size as
the disk on which the image is produced.
Added in version 253.
--architecture=ARCH
This option allows overriding the architecture used for
architecture specific partition types. For example, if set to
"arm64" a partition type of "root-x86-64" referenced in
repart.d/ drop-ins will be patched dynamically to refer to
"root-arm64" instead. Takes one of "alpha", "arc", "arm",
"arm64", "ia64", "loongarch64", "mips-le", "mips64-le",
"parisc", "ppc", "ppc64", "ppc64-le", "riscv32", "riscv64",
"s390", "s390x", "tilegx", "x86" or "x86-64".
Added in version 254.
--offline=BOOL
Instructs systemd-repart to build the image offline. Takes a
boolean or "auto". Defaults to "auto". If enabled, the image
is built without using loop devices. This is useful to build
images unprivileged or when loop devices are not available.
If disabled, the image is always built using loop devices. If
"auto", systemd-repart will build the image online if
possible and fall back to building the image offline if loop
devices are not available or cannot be accessed due to
missing permissions.
Added in version 254.
--copy-from=IMAGE
Instructs systemd-repart to synthesize partition definitions
from the partition table in the given image. This option can
be specified multiple times to synthesize definitions from
each of the given images. The generated definitions will copy
the partitions into the destination partition table. The
copied partitions will have the same size, metadata and
contents but might have a different partition number and
might be located at a different offset in the destination
partition table. These definitions can be combined with
partition definitions read from regular partition definition
files. The synthesized definitions take precedence over the
definitions read from partition definition files.
Added in version 255.
--copy-source=PATH, -s PATH
Specifies a source directory all CopyFiles= source paths
shall be considered relative to. This is similar to --root=,
but exclusively applies to the CopyFiles= setting. If --root=
and --copy-source= are used in combination the former applies
as usual, except for CopyFiles= where the latter takes
precedence.
Added in version 255.
--make-ddi=TYPE
Takes one of "sysext", "confext" or "portable". Generates a
Discoverable Disk Image (DDI) for a system extension (sysext,
see systemd-sysext(8) for details), configuration extension
(confext) or portable service[1]. The generated image will
consist of a signed Verity "erofs" file system as root
partition. In this mode of operation the partition
definitions in /usr/lib/repart.d/*.conf and related
directories are not read, and --definitions= is not
supported, as appropriate definitions for the selected DDI
class will be chosen automatically.
Must be used in conjunction with --copy-source= to specify
the file hierarchy to populate the DDI with. The specified
directory should contain an etc/ subdirectory if "confext" is
selected. If "sysext" is selected it should contain either a
usr/ or opt/ directory, or both. If "portable" is used a full
OS file hierarchy can be provided.
This option implies --empty=create, --size=auto and
--seed=random (the latter two can be overridden).
The private key and certificate for signing the DDI must be
specified via the --private-key= and --certificate= switches.
Added in version 255.
-S, -C, -P
Shortcuts for --make-ddi=sysext, --make-ddi=confext,
--make-ddi=portable, respectively.
Added in version 255.
--generate-fstab=PATH
Specifies a path where to write fstab entries for the
mountpoints configured with MountPoint= in the root directory
specified with --copy-source= or --root= or in the host's
root directory if neither is specified. Disabled by default.
Added in version 256.
--generate-crypttab=PATH
Specifies a path where to write crypttab entries for the
encrypted volumes configured with EncryptedVolume= in the
root directory specified with --copy-source= or --root= or in
the host's root directory if neither is specified. Disabled
by default.
Added in version 256.
-h, --help
Print a short help text and exit.
--version
Print a short version string and exit.
--no-pager
Do not pipe output into a pager.
--no-legend
Do not print the legend, i.e. column headers and the footer
with hints.
--json=MODE
Shows output formatted as JSON. Expects one of "short" (for
the shortest possible output without any redundant whitespace
or line breaks), "pretty" (for a pretty version of the same,
with indentation and line breaks) or "off" (to turn off JSON
output, the default).
On success, 0 is returned, a non-zero failure code otherwise.
Example 1. Generate a configuration extension image
The following creates a configuration extension DDI (confext) for
an /etc/motd update:
mkdir tree tree/etc tree/etc/extension-release.d
echo "Hello World" > tree/etc/motd
cat > tree/etc/extension-release.d/extension-release.my-motd <<EOF
ID=fedora
VERSION_ID=38
IMAGE_ID=my-motd
IMAGE_VERSION=7
EOF
systemd-repart -C --private-key=privkey.pem --certificate=cert.crt -s tree/ /var/lib/confexts/my-motd.confext.raw
systemd-confext refresh
The DDI generated that way may be applied to the system with
systemd-confext(1).
Example 2. Generate a system extension image and sign it via
PKCS11
The following creates a system extension DDI (sysext) for an
/usr/foo update and signs it with a hardware token via PKCS11.
mkdir tree tree/usr tree/usr/lib/extension-release.d
echo "Hello World" > tree/usr/foo
cat > tree/usr/lib/extension-release.d/extension-release.my-foo <<EOF
ID=fedora
VERSION_ID=38
IMAGE_ID=my-foo
IMAGE_VERSION=7
EOF
systemd-repart --make-ddi=sysext --private-key-source=engine:pkcs11 --private-key="pkcs11:model=PKCS%2315%20emulated;manufacturer=piv_II;serial=0123456789abcdef;token=Some%20Cert" --certificate=cert.crt -s tree/ /var/lib/extensions/my-foo.sysext.raw
systemd-sysext refresh
The DDI generated that way may be applied to the system with
systemd-sysext(1).
systemd(1), repart.d(5), machine-id(5), systemd-cryptenroll(1),
portablectl(1), systemd-sysext(8)
1. portable service
https://systemd.io/PORTABLE_SERVICES
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 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-13.) 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 257~devel SYSTEMD-REPART(8)
Pages that refer to this page: repart.d(5), sysupdate.d(5), systemd.directives(7), systemd.index(7), [email protected](8), systemd-pcrlock(8), systemd-sysupdate(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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