SYSTEMD-SYSUPDATE(8) systemd-sysupdate SYSTEMD-SYSUPDATE(8)
NAME
systemd-sysupdate, systemd-sysupdate.service, systemd-sysupdate.timer,
systemd-sysupdate-reboot.service, systemd-sysupdate-reboot.timer -
Automatically Update OS or Other Resources
SYNOPSIS
systemd-sysupdate [OPTIONS...]
systemd-sysupdate.service
DESCRIPTION
systemd-sysupdate atomically updates the host OS, container images,
portable service images or other sources, based on the transfer
configuration files described in sysupdate.d(5).
This tool implements file, directory, or partition based update schemes,
supporting multiple parallel installed versions of specific resources in
an A/B (or even: A/B/C, A/B/C/D/, ...) style. A/B updating means that
when one version of a resource is currently being used, the next version
can be downloaded, unpacked, and prepared in an entirely separate
location, independently of the first, and — once complete — be
activated, swapping the roles so that it becomes the used one and the
previously used one becomes the one that is replaced by the next update,
and so on. The resources to update are defined in transfer files, one
for each resource to be updated. For example, resources that may be
updated with this tool could be: a root file system partition, a
matching Verity partition plus one kernel image. The combination of the
three would be considered a complete OS update.
The tool updates partitions, files or directory trees always in whole,
and operates with at least two versions of each of these resources: the
current version, plus the next version: the one that is being updated
to, and which is initially incomplete as the downloaded data is written
to it; plus optionally more versions. Once the download of a newer
version is complete it becomes the current version, releasing the
version previously considered current for deletion/replacement/updating.
When installing new versions the tool will directly download,
decompress, unpack and write the new version into the destination. This
is done in a robust fashion so that an incomplete download can be
recognized on next invocation, and flushed out before a new attempt is
initiated.
Note that when writing updates to a partition, the partition has to
exist already, as systemd-sysupdate will not automatically create new
partitions. Use a tool such as systemd-repart(8) to automatically create
additional partitions to be used with systemd-sysupdate on boot.
The tool can both be used on the running OS, to update the OS in
"online" state from within itself, and on "offline" disk images, to
update them from the outside based on transfer files embedded in the
disk images. For the latter, see --image= below. The latter is
particularly interesting to update container images or portable service
images.
The systemd-sysupdate.service system service will automatically update
the host OS based on the installed transfer files. It is triggered in
regular intervals via systemd-sysupdate.timer. The
systemd-sysupdate-reboot.service will automatically reboot the system
after a new version is installed. It is triggered via
systemd-sysupdate-reboot.timer. The two services are separate from each
other as it is typically advisable to download updates regularly while
the system is up, but delay reboots until the appropriate time (i.e.
typically at night). The two sets of service/timer units may be enabled
separately.
For details about transfer files and examples see sysupdate.d(5).
COMMAND
The following commands are understood:
list [VERSION]
If invoked without an argument, enumerates downloadable and
installed versions, and shows a summarizing table with the
discovered versions and their properties, including whether there's
a newer candidate version to update to. If a version argument is
specified, shows details about the specific version, including the
individual files that need to be transferred to acquire the version.
If no command is explicitly specified this command is implied.
Added in version 251.
features [FEATURE]
If invoked without an argument, enumerates optional features and
shows a summarizing table, including which features are enabled or
disabled. If a feature argument is specified, shows details about
the specific feature, including the transfers that are controlled by
the feature.
Added in version 257.
check-new
Checks if there's a new version available. This internally
enumerates downloadable and installed versions and returns exit
status 0 if there's a new version to update to, non-zero otherwise.
If there is a new version to update to, its version identifier is
written to standard output.
Added in version 251.
update [VERSION]
Installs (updates to) the specified version, or if none is specified
to the newest version available. If the version is already installed
or no newer version available, no operation is executed.
If a new version to install/update to is found, old installed
versions are deleted until at least one new version can be
installed, as configured via InstanceMax= in sysupdate.d(5), or via
the available partition slots of the right type. This implicit
operation can also be invoked explicitly via the vacuum command
described below.
Added in version 251.
vacuum
Deletes old installed versions until the limits configured via
InstanceMax= in sysupdate.d(5) are met again. Normally, it should
not be necessary to invoke this command explicitly, since it is
implicitly invoked whenever a new update is initiated.
Added in version 251.
pending
Checks whether a newer version of the OS is installed than the one
currently running. Returns zero if so, non-zero otherwise. This
compares the newest installed version's identifier with the OS image
version as reported by the IMAGE_VERSION= field in /etc/os-release.
If the former is newer than the latter, an update was apparently
completed but not activated (i.e. rebooted into) yet.
Added in version 251.
reboot
Similar to the pending command but immediately reboots in case a
newer version of the OS has been installed than the one currently
running. This operation can be done implicitly together with the
update command, after a completed update via the --reboot switch,
see below. This command will execute no operation (and return
success) if no update has been installed, and thus the system was
not rebooted.
Added in version 251.
components
Lists components that can be updated. This enumerates the
/etc/sysupdate.*.d/, /run/sysupdate.*.d/ and /usr/lib/sysupdate.*.d/
directories that contain transfer files. This command is useful to
list possible parameters for --component= (see below).
Added in version 251.
-h, --help
Print a short help text and exit.
--version
Print a short version string and exit.
OPTIONS
The following options are understood:
--component=, -C
Selects the component to update. Takes a component name as argument.
This has the effect of slightly altering the search logic for
transfer files. If this switch is not used, the transfer files are
loaded from /etc/sysupdate.d/*.conf, /run/sysupdate.d/*.conf and
/usr/lib/sysupdate.d/*.conf. If this switch is used, the specified
component name is used to alter the directories to look in to be
/etc/sysupdate.component.d/*.conf, /run/sysupdate.component.d/*.conf
and /usr/lib/sysupdate.component.d/*.conf, each time with the
component string replaced with the specified component name.
Use the components command to list available components to update.
This enumerates the directories matching this naming rule.
Components may be used to define a separate set of transfer files
for different components of the OS that shall be updated separately.
Do not use this concept for resources that shall always be updated
together in a synchronous fashion. Simply define multiple transfer
files within the same sysupdate.d/ directory for these cases.
This option may not be combined with --definitions=.
Added in version 251.
--definitions=
A path to a directory. If specified, the transfer *.conf files are
read from this directory instead of /usr/lib/sysupdate.d/*.conf,
/etc/sysupdate.d/*.conf, and /run/sysupdate.d/*.conf.
This option may not be combined with --component=.
Added in version 251.
--root=
Takes a path to a directory to use as root file system when
searching for sysupdate.d/*.conf files.
Added in version 251.
--image=
Takes a path to a disk image file or device to mount and use in a
similar fashion to --root=, see above. If this is used and partition
resources are updated this is done inside the specified disk image.
Added in version 251.
--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.
--instances-max=, -m
Takes a decimal integer greater than or equal to 2 while updating or
1 while vacuuming. Controls how many versions to keep at any time.
This option may also be configured inside the transfer files, via
the InstancesMax= setting, see sysupdate.d(5) for details.
Added in version 251.
--sync=
Takes a boolean argument, defaults to yes. This may be used to
specify whether the newly updated resource versions shall be
synchronized to disk when appropriate (i.e. after the download is
complete, before it is finalized, and again after finalization).
This should not be turned off, except to improve runtime performance
in testing environments.
Added in version 251.
--verify=
Takes a boolean argument, defaults to yes. Controls whether to
cryptographically verify downloads. Do not turn this off, except in
testing environments.
Added in version 251.
--reboot
When used in combination with the update command and a new version
is installed, automatically reboots the system immediately
afterwards.
Added in version 251.
--offline
Prevents fetching metadata from the network (i.e. SHA256SUMS). This
is most useful when used in combination with the list command, to
query locally installed versions.
Added in version 257.
--transfer-source=
Takes a path as its argument. When specified, all transfer sources
configured with PathRelativeTo=explicit will be interpreted relative
to the specified path.
Added in version 257.
--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).
EXIT STATUS
On success, 0 is returned, a non-zero failure code otherwise.
SEE ALSO
systemd(1), sysupdate.d(5), systemd-sysupdated.service(8), systemd-
repart(8)
systemd 257.9 SYSTEMD-SYSUPDATE(8)
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