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.

       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. 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.

       --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-repart(8)