+CHANGES WITH 234:
+
+ * Meson is now supported as build system in addition to Automake. It is
+ our plan to remove Automake in one of our next releases, so that
+ Meson becomes our exclusive build system. Hence, please start using
+ the Meson build system in your downstream packaging. There's plenty
+ of documentation around how to use Meson, the extremely brief
+ summary:
+
+ ./autogen.sh && ./configure && make && sudo make install
+
+ becomes:
+
+ meson build && ninja -C build && sudo ninja -C build install
+
+ * Unit files gained support for a new JobRunningTimeoutUSec= setting,
+ which permits configuring a timeout on the time a job is
+ running. This is particularly useful for setting timeouts on jobs for
+ .device units.
+
+ * Unit files gained two new options ConditionUser= and ConditionGroup=
+ for conditionalizing units based on the identity of the user/group
+ running a systemd user instance.
+
+ * systemd-networkd now understands a new FlowLabel= setting in the
+ [VXLAN] section of .network files, as well as a Priority= in
+ [Bridge], GVRP= + MVRP= + LooseBinding= + ReorderHeader= in [VLAN]
+ and GatewayOnlink= + IPv6Preference= + Protocol= in [Route]. It also
+ gained support for configuration of GENEVE links, and IPv6 address
+ labels. The [Network] section gained the new IPv6ProxyNDP= setting.
+
+ * .link files now understand a new Port= setting.
+
+ * systemd-networkd's DHCP support gained support for DHCP option 119
+ (domain search list).
+
+ * systemd-networkd gained support for serving IPv6 address ranges using
+ the Router Advertisment protocol. The new .network configuration
+ section [IPv6Prefix] may be used to configure the ranges to
+ serve. This is implemented based on a new, minimal, native server
+ implementation of RA.
+
+ * journalctl's --output= switch gained support for a new parameter
+ "short-iso-precise" for a mode where timestamps are shown as precise
+ ISO date values.
+
+ * systemd-udevd's "net_id" builtin may now generate stable network
+ interface names from IBM PowerVM VIO devices as well as ACPI platform
+ devices.
+
+ * MulticastDNS support in systemd-resolved may now be explicitly
+ enabled/disabled using the new MulticastDNS= configuration file
+ option.
+
+ * systemd-resolved may now optionally use libidn2 instead of the libidn
+ for processing internationalized domain names. Support for libidn2
+ should be considered experimental and should not be enabled by
+ default yet.
+
+ * "machinectl pull-tar" and related call may now do verification of
+ downloaded images using SUSE-style .sha256 checksum files in addition
+ to the already existing support for validating using Ubuntu-style
+ SHA256SUMS files.
+
+ * sd-bus gained support for a new sd_bus_message_appendv() call which
+ is va_list equivalent of sd_bus_message_append().
+
+ * sd-boot gained support for validating images using SHIM/MOK.
+
+ * The SMACK code learnt support for "onlycap".
+
+ * systemd-mount --umount is now much smarter in figuring out how to
+ properly unmount a device given its mount or device path.
+
+ * The code to call libnss_dns as a fallback from libnss_resolve when
+ the communication with systemd-resolved fails was removed. This
+ fallback was redundant and interfered with the [!UNAVAIL=return]
+ suffix. See nss-resolve(8) for the recommended configuration.
+
+ * systemd-logind may now be restarted without losing state. It stores
+ the file descriptors for devices it manages in the system manager
+ using the FDSTORE= mechanism. Please note that further changes in
+ other components may be required to make use of this (for example
+ Xorg has code to listen for stops of systemd-logind and terminate
+ itself when logind is stopped or restarted, in order to avoid using
+ stale file descriptors for graphical devices, which is now
+ counterproductive and must be reverted in order for restarts of
+ systemd-logind to be safe. See
+ https://cgit.freedesktop.org/xorg/xserver/commit/?id=dc48bd653c7e101.)
+
+ * All kernel install plugins are called with the environment variable
+ KERNEL_INSTALL_MACHINE_ID which is set to the machine ID given by
+ /etc/machine-id. If the file is missing or empty, the variable is
+ empty and BOOT_DIR_ABS is the path of a temporary directory which is
+ removed after all the plugins exit. So, if KERNEL_INSTALL_MACHINE_ID
+ is empty, all plugins should not put anything in BOOT_DIR_ABS.
+
+ Contributions from: Adrian Heine né Lang, Aggelos Avgerinos, Alexander
+ Kurtz, Alexandros Frantzis, Alexey Brodkin, Alex Lu, Amir Pakdel, Amir
+ Yalon, Anchor Cat, Anthony Parsons, Bastien Nocera, Benjamin Gilbert,
+ Benjamin Robin, Boucman, Charles Plessy, Chris Chiu, Chris Lamb,
+ Christian Brauner, Christian Hesse, Colin Walters, Daniel Drake,
+ Danielle Church, Daniel Molkentin, Daniel Rusek, Daniel Wang, Davide
+ Cavalca, David Herrmann, David Michael, Dax Kelson, Dimitri John
+ Ledkov, Djalal Harouni, Dušan Kazik, Elias Probst, Evgeny Vereshchagin,
+ Federico Di Pierro, Felipe Sateler, Felix Zhang, Franck Bui, Gary
+ Tierney, George McCollister, Giedrius Statkevičius, Hans de Goede,
+ hecke, Hendrik Westerberg, Hristo Venev, Ian Wienand, Insun Pyo, Ivan
+ Shapovalov, James Cowgill, James Hemsing, Janne Heß, Jan Synacek, Jason
+ Reeder, João Paulo Rechi Vita, John Paul Adrian Glaubitz, Jörg
+ Thalheim, Josef Andersson, Josef Gajdusek, Julian Mehne, Kai Krakow,
+ Krzysztof Jackiewicz, Lars Karlitski, Lennart Poettering, Lluís Gili,
+ Lucas Werkmeister, Lukáš Nykrýn, Łukasz Stelmach, Mantas Mikulėnas,
+ Marcin Bachry, Marcus Cooper, Mark Stosberg, Martin Pitt, Matija Skala,
+ Matt Clarkson, Matthew Garrett, Matthias Greiner, Matthijs van Duin,
+ Max Resch, Michael Biebl, Michal Koutný, Michal Sekletar, Michal
+ Soltys, Michal Suchanek, Mike Gilbert, Nate Clark, Nathaniel R. Lewis,
+ Neil Brown, Nikolai Kondrashov, Pascal S. de Kloe, Pat Riehecky, Patrik
+ Flykt, Paul Kocialkowski, Peter Hutterer, Philip Withnall, Piotr
+ Szydełko, Rafael Fontenelle, Ray Strode, Richard Maw, Roelf Wichertjes,
+ Ronny Chevalier, Sarang S. Dalal, Sjoerd Simons, slodki, Stefan
+ Schweter, Susant Sahani, Ted Wood, Thomas Blume, Thomas Haller, Thomas
+ H. P. Andersen, Timothée Ravier, Tobias Jungel, Tobias Stoeckmann, Tom
+ Gundersen, Tom Yan, Torstein Husebø, Umut Tezduyar Lindskog,
+ userwithuid, Vito Caputo, Waldemar Brodkorb, WaLyong Cho, Yu, Li-Yu,
+ Yusuke Nojima, Yu Watanabe, Zbigniew Jędrzejewski-Szmek, Дамјан
+ Георгиевски
+
+ — Berlin, 2017-07-12
+
+CHANGES WITH 233:
+
+ * This version requires at least gperf 3.1 for building, 3.0 is not
+ sufficient.
+
+ * The "hybrid" control group mode has been modified to improve
+ compatibility with "legacy" cgroups-v1 setups. Specifically, the
+ "hybrid" setup of /sys/fs/cgroup is now pretty much identical to
+ "legacy" (including /sys/fs/cgroup/systemd as "name=systemd" named
+ cgroups-v1 hierarchy), the only externally visible change being that
+ the cgroups-v2 hierarchy is also mounted, to
+ /sys/fs/cgroup/unified. This should provide a large degree of
+ compatibility with "legacy" cgroups-v1, while taking benefit of the
+ better management capabilities of cgroups-v2.
+
+ * The default control group setup mode may be selected both a boot-time
+ via a set of kernel command line parameters (specifically:
+ systemd.unified_cgroup_hierarchy= and
+ systemd.legacy_systemd_cgroup_controller=), as well as a compile-time
+ default selected on the configure command line
+ (--with-default-hierarchy=). The upstream default is "hybrid"
+ (i.e. the cgroups-v1 + cgroups-v2 mixture discussed above) now, but
+ this will change in a future systemd version to be "unified" (pure
+ cgroups-v2 mode). The third option for the compile time option is
+ "legacy", to enter pure cgroups-v1 mode. We recommend downstream
+ distributions to default to "hybrid" mode for release distributions,
+ starting with v233. We recommend "unified" for development
+ distributions (specifically: distributions such as Fedora's rawhide)
+ as that's where things are headed in the long run. Use "legacy" for
+ greatest stability and compatibility only.
+
+ * Note one current limitation of "unified" and "hybrid" control group
+ setup modes: the kernel currently does not permit the systemd --user
+ instance (i.e. unprivileged code) to migrate processes between two
+ disconnected cgroup subtrees, even if both are managed and owned by
+ the user. This effectively means "systemd-run --user --scope" doesn't
+ work when invoked from outside of any "systemd --user" service or
+ scope. Specifically, it is not supported from session scopes. We are
+ working on fixing this in a future systemd version. (See #3388 for
+ further details about this.)
+
+ * DBus policy files are now installed into /usr rather than /etc. Make
+ sure your system has dbus >= 1.9.18 running before upgrading to this
+ version, or override the install path with --with-dbuspolicydir= .
+
+ * All python scripts shipped with systemd (specifically: the various
+ tests written in Python) now require Python 3.
+
+ * systemd unit tests can now run standalone (without the source or
+ build directories), and can be installed into /usr/lib/systemd/tests/
+ with 'make install-tests'.
+
+ * Note that from this version on, CONFIG_CRYPTO_USER_API_HASH,
+ CONFIG_CRYPTO_HMAC and CONFIG_CRYPTO_SHA256 need to be enabled in the
+ kernel.
+
+ * Support for the %c, %r, %R specifiers in unit files has been
+ removed. Specifiers are not supposed to be dependent on configuration
+ in the unit file itself (so that they resolve the same regardless
+ where used in the unit files), but these specifiers were influenced
+ by the Slice= option.
+
+ * The shell invoked by debug-shell.service now defaults to /bin/sh in
+ all cases. If distributions want to use a different shell for this
+ purpose (for example Fedora's /sbin/sushell) they need to specify
+ this explicitly at configure time using --with-debug-shell=.
+
+ * The confirmation spawn prompt has been reworked to offer the
+ following choices:
+
+ (c)ontinue, proceed without asking anymore
+ (D)ump, show the state of the unit
+ (f)ail, don't execute the command and pretend it failed
+ (h)elp
+ (i)nfo, show a short summary of the unit
+ (j)obs, show jobs that are in progress
+ (s)kip, don't execute the command and pretend it succeeded
+ (y)es, execute the command
+
+ The 'n' choice for the confirmation spawn prompt has been removed,
+ because its meaning was confusing.
+
+ The prompt may now also be redirected to an alternative console by
+ specifying the console as parameter to systemd.confirm_spawn=.
+
+ * Services of Type=notify require a READY=1 notification to be sent
+ during startup. If no such message is sent, the service now fails,
+ even if the main process exited with a successful exit code.
+
+ * Services that fail to start up correctly now always have their
+ ExecStopPost= commands executed. Previously, they'd enter "failed"
+ state directly, without executing these commands.
+
+ * The option MulticastDNS= of network configuration files has acquired
+ an actual implementation. With MulticastDNS=yes a host can resolve
+ names of remote hosts and reply to mDNS A and AAAA requests.
+
+ * When units are about to be started an additional check is now done to
+ ensure that all dependencies of type BindsTo= (when used in
+ combination with After=) have been started.
+
+ * systemd-analyze gained a new verb "syscall-filter" which shows which
+ system call groups are defined for the SystemCallFilter= unit file
+ setting, and which system calls they contain.
+
+ * A new system call filter group "@filesystem" has been added,
+ consisting of various file system related system calls. Group
+ "@reboot" has been added, covering reboot, kexec and shutdown related
+ calls. Finally, group "@swap" has been added covering swap
+ configuration related calls.
+
+ * A new unit file option RestrictNamespaces= has been added that may be
+ used to restrict access to the various process namespace types the
+ Linux kernel provides. Specifically, it may be used to take away the
+ right for a service unit to create additional file system, network,
+ user, and other namespaces. This sandboxing option is particularly
+ relevant due to the high amount of recently discovered namespacing
+ related vulnerabilities in the kernel.
+
+ * systemd-udev's .link files gained support for a new AutoNegotiation=
+ setting for configuring Ethernet auto-negotiation.
+
+ * systemd-networkd's .network files gained support for a new
+ ListenPort= setting in the [DHCP] section to explicitly configure the
+ UDP client port the DHCP client shall listen on.
+
+ * .network files gained a new Unmanaged= boolean setting for explicitly
+ excluding one or more interfaces from management by systemd-networkd.
+
+ * The systemd-networkd ProxyARP= option has been renamed to
+ IPV4ProxyARP=. Similarly, VXLAN-specific option ARPProxy= has been
+ renamed to ReduceARPProxy=. The old names continue to be available
+ for compatibility.
+
+ * systemd-networkd gained support for configuring IPv6 Proxy NDP
+ addresses via the new IPv6ProxyNDPAddress= .network file setting.
+
+ * systemd-networkd's bonding device support gained support for two new
+ configuration options ActiveSlave= and PrimarySlave=.
+
+ * The various options in the [Match] section of .network files gained
+ support for negative matching.
+
+ * New systemd-specific mount options are now understood in /etc/fstab:
+
+ x-systemd.mount-timeout= may be used to configure the maximum
+ permitted runtime of the mount command.
+
+ x-systemd.device-bound may be set to bind a mount point to its
+ backing device unit, in order to automatically remove a mount point
+ if its backing device is unplugged. This option may also be
+ configured through the new SYSTEMD_MOUNT_DEVICE_BOUND udev property
+ on the block device, which is now automatically set for all CDROM
+ drives, so that mounted CDs are automatically unmounted when they are
+ removed from the drive.
+
+ x-systemd.after= and x-systemd.before= may be used to explicitly
+ order a mount after or before another unit or mount point.
+
+ * Enqueued start jobs for device units are now automatically garbage
+ collected if there are no jobs waiting for them anymore.
+
+ * systemctl list-jobs gained two new switches: with --after, for every
+ queued job the jobs it's waiting for are shown; with --before the
+ jobs which it's blocking are shown.
+
+ * systemd-nspawn gained support for ephemeral boots from disk images
+ (or in other words: --ephemeral and --image= may now be
+ combined). Moreover, ephemeral boots are now supported for normal
+ directories, even if the backing file system is not btrfs. Of course,
+ if the file system does not support file system snapshots or
+ reflinks, the initial copy operation will be relatively expensive, but
+ this should still be suitable for many use cases.
+
+ * Calendar time specifications in .timer units now support
+ specifications relative to the end of a month by using "~" instead of
+ "-" as separator between month and day. For example, "*-02~03" means
+ "the third last day in February". In addition a new syntax for
+ repeated events has been added using the "/" character. For example,
+ "9..17/2:00" means "every two hours from 9am to 5pm".
+
+ * systemd-socket-proxyd gained a new parameter --connections-max= for
+ configuring the maximum number of concurrent connections.
+
+ * sd-id128 gained a new API for generating unique IDs for the host in a
+ way that does not leak the machine ID. Specifically,
+ sd_id128_get_machine_app_specific() derives an ID based on the
+ machine ID a in well-defined, non-reversible, stable way. This is
+ useful whenever an identifier for the host is needed but where the
+ identifier shall not be useful to identify the system beyond the
+ scope of the application itself. (Internally this uses HMAC-SHA256 as
+ keyed hash function using the machine ID as input.)
+
+ * NotifyAccess= gained a new supported value "exec". When set
+ notifications are accepted from all processes systemd itself invoked,
+ including all control processes.
+
+ * .nspawn files gained support for defining overlay mounts using the
+ Overlay= and OverlayReadOnly= options. Previously this functionality
+ was only available on the systemd-nspawn command line.
+
+ * systemd-nspawn's --bind= and --overlay= options gained support for
+ bind/overlay mounts whose source lies within the container tree by
+ prefixing the source path with "+".
+
+ * systemd-nspawn's --bind= and --overlay= options gained support for
+ automatically allocating a temporary source directory in /var/tmp
+ that is removed when the container dies. Specifically, if the source
+ directory is specified as empty string this mechanism is selected. An
+ example usage is --overlay=+/var::/var, which creates an overlay
+ mount based on the original /var contained in the image, overlayed
+ with a temporary directory in the host's /var/tmp. This way changes
+ to /var are automatically flushed when the container shuts down.
+
+ * systemd-nspawn --image= option does now permit raw file system block
+ devices (in addition to images containing partition tables, as
+ before).
+
+ * The disk image dissection logic in systemd-nspawn gained support for
+ automatically setting up LUKS encrypted as well as Verity protected
+ partitions. When a container is booted from an encrypted image the
+ passphrase is queried at start-up time. When a container with Verity
+ data is started, the root hash is search in a ".roothash" file
+ accompanying the disk image (alternatively, pass the root hash via
+ the new --root-hash= command line option).
+
+ * A new tool /usr/lib/systemd/systemd-dissect has been added that may
+ be used to dissect disk images the same way as systemd-nspawn does
+ it, following the Bootable Partition Specification. It may even be
+ used to mount disk images with complex partition setups (including
+ LUKS and Verity partitions) to a local host directory, in order to
+ inspect them. This tool is not considered public API (yet), and is
+ thus not installed into /usr/bin. Please do not rely on its
+ existence, since it might go away or be changed in later systemd
+ versions.
+
+ * A new generator "systemd-verity-generator" has been added, similar in
+ style to "systemd-cryptsetup-generator", permitting automatic setup of
+ Verity root partitions when systemd boots up. In order to make use of
+ this your partition setup should follow the Discoverable Partitions
+ Specification, and the GPT partition ID of the root file system
+ partition should be identical to the upper 128bit of the Verity root
+ hash. The GPT partition ID of the Verity partition protecting it
+ should be the lower 128bit of the Verity root hash. If the partition
+ image follows this model it is sufficient to specify a single
+ "roothash=" kernel command line argument to both configure which root
+ image and verity partition to use as well as the root hash for
+ it. Note that systemd-nspawn's Verity support follows the same
+ semantics, meaning that disk images with proper Verity data in place
+ may be booted in containers with systemd-nspawn as well as on
+ physical systems via the verity generator. Also note that the "mkosi"
+ tool available at https://github.com/systemd/mkosi has been updated
+ to generate Verity protected disk images following this scheme. In
+ fact, it has been updated to generate disk images that optionally
+ implement a complete UEFI SecureBoot trust chain, involving a signed
+ kernel and initrd image that incorporates such a root hash as well as
+ a Verity-enabled root partition.
+
+ * The hardware database (hwdb) udev supports has been updated to carry
+ accelerometer quirks.
+
+ * All system services are now run with a fresh kernel keyring set up
+ for them. The invocation ID is stored by default in it, thus
+ providing a safe, non-overridable way to determine the invocation
+ ID of each service.
+
+ * Service unit files gained new BindPaths= and BindReadOnlyPaths=
+ options for bind mounting arbitrary paths in a service-specific
+ way. When these options are used, arbitrary host or service files and
+ directories may be mounted to arbitrary locations in the service's
+ view.
+
+ * Documentation has been added that lists all of systemd's low-level
+ environment variables:
+
+ https://github.com/systemd/systemd/blob/master/ENVIRONMENT.md
+
+ * sd-daemon gained a new API sd_is_socket_sockaddr() for determining
+ whether a specific socket file descriptor matches a specified socket
+ address.
+
+ * systemd-firstboot has been updated to check for the
+ systemd.firstboot= kernel command line option. It accepts a boolean
+ and when set to false the first boot questions are skipped.
+
+ * systemd-fstab-generator has been updated to check for the
+ systemd.volatile= kernel command line option, which either takes an
+ optional boolean parameter or the special value "state". If used the
+ system may be booted in a "volatile" boot mode. Specifically,
+ "systemd.volatile" is used, the root directory will be mounted as
+ tmpfs, and only /usr is mounted from the actual root file system. If
+ "systemd.volatile=state" is used, the root directory will be mounted
+ as usual, but /var is mounted as tmpfs. This concept provides similar
+ functionality as systemd-nspawn's --volatile= option, but provides it
+ on physical boots. Use this option for implementing stateless
+ systems, or testing systems with all state and/or configuration reset
+ to the defaults. (Note though that many distributions are not
+ prepared to boot up without a populated /etc or /var, though.)
+
+ * systemd-gpt-auto-generator gained support for LUKS encrypted root
+ partitions. Previously it only supported LUKS encrypted partitions
+ for all other uses, except for the root partition itself.
+
+ * Socket units gained support for listening on AF_VSOCK sockets for
+ communication in virtualized QEMU environments.
+
+ * The "configure" script gained a new option --with-fallback-hostname=
+ for specifying the fallback hostname to use if none is configured in
+ /etc/hostname. For example, by specifying
+ --with-fallback-hostname=fedora it is possible to default to a
+ hostname of "fedora" on pristine installations.
+
+ * systemd-cgls gained support for a new --unit= switch for listing only
+ the control groups of a specific unit. Similar --user-unit= has been
+ added for listing only the control groups of a specific user unit.
+
+ * systemd-mount gained a new --umount switch for unmounting a mount or
+ automount point (and all mount/automount points below it).
+
+ * systemd will now refuse full configuration reloads (via systemctl
+ daemon-reload and related calls) unless at least 16MiB of free space
+ are available in /run. This is a safety precaution in order to ensure
+ that generators can safely operate after the reload completed.
+
+ * A new unit file option RootImage= has been added, which has a similar
+ effect as RootDirectory= but mounts the service's root directory from
+ a disk image instead of plain directory. This logic reuses the same
+ image dissection and mount logic that systemd-nspawn already uses,
+ and hence supports any disk images systemd-nspawn supports, including
+ those following the Discoverable Partition Specification, as well as
+ Verity enabled images. This option enables systemd to run system
+ services directly off disk images acting as resource bundles,
+ possibly even including full integrity data.
+
+ * A new MountAPIVFS= unit file option has been added, taking a boolean
+ argument. If enabled /proc, /sys and /dev (collectively called the
+ "API VFS") will be mounted for the service. This is only relevant if
+ RootDirectory= or RootImage= is used for the service, as these mounts
+ are of course in place in the host mount namespace anyway.
+
+ * systemd-nspawn gained support for a new --pivot-root= switch. If
+ specified the root directory within the container image is pivoted to
+ the specified mount point, while the original root disk is moved to a
+ different place. This option enables booting of ostree images
+ directly with systemd-nspawn.
+
+ * The systemd build scripts will no longer complain if the NTP server
+ addresses are not changed from the defaults. Google now supports
+ these NTP servers officially. We still recommend downstreams to
+ properly register an NTP pool with the NTP pool project though.
+
+ * coredumpctl gained a new "--reverse" option for printing the list
+ of coredumps in reverse order.
+
+ * coredumpctl will now show additional information about truncated and
+ inaccessible coredumps, as well as coredumps that are still being
+ processed. It also gained a new --quiet switch for suppressing
+ additional informational message in its output.
+
+ * coredumpctl gained support for only showing coredumps newer and/or
+ older than specific timestamps, using the new --since= and --until=
+ options, reminiscent of journalctl's options by the same name.
+
+ * The systemd-coredump logic has been improved so that it may be reused
+ to collect backtraces in non-compiled languages, for example in
+ scripting languages such as Python.
+
+ * machinectl will now show the UID shift of local containers, if user
+ namespacing is enabled for them.
+
+ * systemd will now optionally run "environment generator" binaries at
+ configuration load time. They may be used to add environment
+ variables to the environment block passed to services invoked. One
+ user environment generator is shipped by default that sets up
+ environment variables based on files dropped into /etc/environment.d
+ and ~/.config/environment.d/.
+
+ * systemd-resolved now includes the new, recently published 2017 DNSSEC
+ root key (KSK).
+
+ * hostnamed has been updated to report a new chassis type of
+ "convertible" to cover "foldable" laptops that can both act as a
+ tablet and as a laptop, such as various Lenovo Yoga devices.
+
+ Contributions from: Adrián López, Alexander Galanin, Alexander
+ Kochetkov, Alexandros Frantzis, Andrey Ulanov, Antoine Eiche, Baruch
+ Siach, Bastien Nocera, Benjamin Robin, Björn, Brandon Philips, Cédric
+ Schieli, Charles (Chas) Williams, Christian Hesse, Daniele Medri,
+ Daniel Drake, Daniel Rusek, Daniel Wagner, Dan Streetman, Dave Reisner,
+ David Glasser, David Herrmann, David Michael, Djalal Harouni, Dmitry
+ Khlebnikov, Dmitry Rozhkov, Dongsu Park, Douglas Christman, Earnestly,
+ Emil Soleyman, Eric Cook, Evgeny Vereshchagin, Felipe Sateler, Fionn
+ Cleary, Florian Klink, Francesco Brozzu, Franck Bui, Gabriel Rauter,
+ Gianluca Boiano, Giedrius Statkevičius, Graeme Lawes, Hans de Goede,
+ Harald Hoyer, Ian Kelling, Ivan Shapovalov, Jakub Wilk, Janne Heß, Jan
+ Synacek, Jason Reeder, Jonathan Boulle, Jörg Thalheim, Jouke Witteveen,
+ Karl Kraus, Kees Cook, Keith Busch, Kieran Colford, kilian-k, Lennart
+ Poettering, Lubomir Rintel, Lucas Werkmeister, Lukas Rusak, Maarten de
+ Vries, Maks Naumov, Mantas Mikulėnas, Marc-Andre Lureau, Marcin Bachry,
+ Mark Stosberg, Martin Ejdestig, Martin Pitt, Mauricio Faria de
+ Oliveira, micah, Michael Biebl, Michael Shields, Michal Schmidt, Michal
+ Sekletar, Michel Kraus, Mike Gilbert, Mikko Ylinen, Mirza Krak,
+ Namhyung Kim, nikolaof, peoronoob, Peter Hutterer, Peter Körner, Philip
+ Withnall, Piotr Drąg, Ray Strode, Reverend Homer, Rike-Benjamin
+ Schuppner, Robert Kreuzer, Ronny Chevalier, Ruslan Bilovol, sammynx,
+ Sergey Ptashnick, Sergiusz Urbaniak, Stefan Berger, Stefan Hajnoczi,
+ Stefan Schweter, Stuart McLaren, Susant Sahani, Sylvain Plantefève,
+ Taylor Smock, Tejun Heo, Thomas Blume, Thomas H. P. Andersen, Tibor
+ Nagy, Tobias Stoeckmann, Tom Gundersen, Torstein Husebø, Viktar
+ Vaŭčkievič, Viktor Mihajlovski, Vitaly Sulimov, Waldemar Brodkorb,
+ Walter Garcia-Fontes, Wim de With, Yassine Imounachen, Yi EungJun,
+ YunQiang Su, Yu Watanabe, Zbigniew Jędrzejewski-Szmek, Александр
+ Тихонов
+
+ — Berlin, 2017-03-01
+
+CHANGES WITH 232:
+
+ * udev now runs with MemoryDenyWriteExecute=, RestrictRealtime= and
+ RestrictAddressFamilies= enabled. These sandboxing options should
+ generally be compatible with the various external udev call-out
+ binaries we are aware of, however there may be exceptions, in
+ particular when exotic languages for these call-outs are used. In
+ this case, consider turning off these settings locally.
+
+ * The new RemoveIPC= option can be used to remove IPC objects owned by
+ the user or group of a service when that service exits.
+
+ * The new ProtectKernelModules= option can be used to disable explicit
+ load and unload operations of kernel modules by a service. In
+ addition access to /usr/lib/modules is removed if this option is set.
+
+ * ProtectSystem= option gained a new value "strict", which causes the
+ whole file system tree with the exception of /dev, /proc, and /sys,
+ to be remounted read-only for a service.
+
+ * The new ProtectKernelTunables= option can be used to disable
+ modification of configuration files in /sys and /proc by a service.
+ Various directories and files are remounted read-only, so access is
+ restricted even if the file permissions would allow it.
+
+ * The new ProtectControlGroups= option can be used to disable write
+ access by a service to /sys/fs/cgroup.
+
+ * Various systemd services have been hardened with
+ ProtectKernelTunables=yes, ProtectControlGroups=yes,
+ RestrictAddressFamilies=.
+
+ * Support for dynamically creating users for the lifetime of a service
+ has been added. If DynamicUser=yes is specified, user and group IDs
+ will be allocated from the range 61184..65519 for the lifetime of the
+ service. They can be resolved using the new nss-systemd.so NSS
+ module. The module must be enabled in /etc/nsswitch.conf. Services
+ started in this way have PrivateTmp= and RemoveIPC= enabled, so that
+ any resources allocated by the service will be cleaned up when the
+ service exits. They also have ProtectHome=read-only and
+ ProtectSystem=strict enabled, so they are not able to make any
+ permanent modifications to the system.
+
+ * The nss-systemd module also always resolves root and nobody, making
+ it possible to have no /etc/passwd or /etc/group files in minimal
+ container or chroot environments.
+
+ * Services may be started with their own user namespace using the new
+ boolean PrivateUsers= option. Only root, nobody, and the uid/gid
+ under which the service is running are mapped. All other users are
+ mapped to nobody.
+
+ * Support for the cgroup namespace has been added to systemd-nspawn. If
+ supported by kernel, the container system started by systemd-nspawn
+ will have its own view of the cgroup hierarchy. This new behaviour
+ can be disabled using $SYSTEMD_NSPAWN_USE_CGNS environment variable.
+
+ * The new MemorySwapMax= option can be used to limit the maximum swap
+ usage under the unified cgroup hierarchy.
+
+ * Support for the CPU controller in the unified cgroup hierarchy has
+ been added, via the CPUWeight=, CPUStartupWeight=, CPUAccounting=
+ options. This controller requires out-of-tree patches for the kernel
+ and the support is provisional.
+
+ * Mount and automount units may now be created transiently
+ (i.e. dynamically at runtime via the bus API, instead of requiring
+ unit files in the file system).
+
+ * systemd-mount is a new tool which may mount file systems – much like
+ mount(8), optionally pulling in additional dependencies through
+ transient .mount and .automount units. For example, this tool
+ automatically runs fsck on a backing block device before mounting,
+ and allows the automount logic to be used dynamically from the
+ command line for establishing mount points. This tool is particularly
+ useful when dealing with removable media, as it will ensure fsck is
+ run – if necessary – before the first access and that the file system
+ is quickly unmounted after each access by utilizing the automount
+ logic. This maximizes the chance that the file system on the
+ removable media stays in a clean state, and if it isn't in a clean
+ state is fixed automatically.
+
+ * LazyUnmount=yes option for mount units has been added to expose the
+ umount --lazy option. Similarly, ForceUnmount=yes exposes the --force
+ option.
+
+ * /efi will be used as the mount point of the EFI boot partition, if
+ the directory is present, and the mount point was not configured
+ through other means (e.g. fstab). If /efi directory does not exist,
+ /boot will be used as before. This makes it easier to automatically
+ mount the EFI partition on systems where /boot is used for something
+ else.
+
+ * When operating on GPT disk images for containers, systemd-nspawn will
+ now mount the ESP to /boot or /efi according to the same rules as PID
+ 1 running on a host. This allows tools like "bootctl" to operate
+ correctly within such containers, in order to make container images
+ bootable on physical systems.
+
+ * disk/by-id and disk/by-path symlinks are now created for NVMe drives.
+
+ * Two new user session targets have been added to support running
+ graphical sessions under the systemd --user instance:
+ graphical-session.target and graphical-session-pre.target. See
+ systemd.special(7) for a description of how those targets should be
+ used.
+
+ * The vconsole initialization code has been significantly reworked to
+ use KD_FONT_OP_GET/SET ioctls instead of KD_FONT_OP_COPY and better
+ support unicode keymaps. Font and keymap configuration will now be
+ copied to all allocated virtual consoles.
+
+ * FreeBSD's bhyve virtualization is now detected.
+
+ * Information recorded in the journal for core dumps now includes the
+ contents of /proc/mountinfo and the command line of the process at
+ the top of the process hierarchy (which is usually the init process
+ of the container).
+
+ * systemd-journal-gatewayd learned the --directory= option to serve
+ files from the specified location.
+
+ * journalctl --root=… can be used to peruse the journal in the
+ /var/log/ directories inside of a container tree. This is similar to
+ the existing --machine= option, but does not require the container to
+ be active.
+
+ * The hardware database has been extended to support
+ ID_INPUT_TRACKBALL, used in addition to ID_INPUT_MOUSE to identify
+ trackball devices.
+
+ MOUSE_WHEEL_CLICK_ANGLE_HORIZONTAL hwdb property has been added to
+ specify the click rate for mice which include a horizontal wheel with
+ a click rate that is different than the one for the vertical wheel.
+
+ * systemd-run gained a new --wait option that makes service execution
+ synchronous. (Specifically, the command will not return until the
+ specified service binary exited.)
+
+ * systemctl gained a new --wait option that causes the start command to
+ wait until the units being started have terminated again.
+
+ * A new journal output mode "short-full" has been added which displays
+ timestamps with abbreviated English day names and adds a timezone
+ suffix. Those timestamps include more information than the default
+ "short" output mode, and can be passed directly to journalctl's
+ --since= and --until= options.
+
+ * /etc/resolv.conf will be bind-mounted into containers started by
+ systemd-nspawn, if possible, so any changes to resolv.conf contents
+ are automatically propagated to the container.
+
+ * The number of instances for socket-activated services originating
+ from a single IP address can be limited with
+ MaxConnectionsPerSource=, extending the existing setting of
+ MaxConnections=.
+
+ * systemd-networkd gained support for vcan ("Virtual CAN") interface
+ configuration.
+
+ * .netdev and .network configuration can now be extended through
+ drop-ins.
+
+ * UDP Segmentation Offload, TCP Segmentation Offload, Generic
+ Segmentation Offload, Generic Receive Offload, Large Receive Offload
+ can be enabled and disabled using the new UDPSegmentationOffload=,
+ TCPSegmentationOffload=, GenericSegmentationOffload=,
+ GenericReceiveOffload=, LargeReceiveOffload= options in the
+ [Link] section of .link files.
+
+ * The Spanning Tree Protocol, Priority, Aging Time, and the Default
+ Port VLAN ID can be configured for bridge devices using the new STP=,
+ Priority=, AgeingTimeSec=, and DefaultPVID= settings in the [Bridge]
+ section of .netdev files.
+
+ * The route table to which routes received over DHCP or RA should be
+ added can be configured with the new RouteTable= option in the [DHCP]
+ and [IPv6AcceptRA] sections of .network files.
+
+ * The Address Resolution Protocol can be disabled on links managed by
+ systemd-networkd using the ARP=no setting in the [Link] section of
+ .network files.
+
+ * New environment variables $SERVICE_RESULT, $EXIT_CODE and
+ $EXIT_STATUS are set for ExecStop= and ExecStopPost= commands, and
+ encode information about the result and exit codes of the current
+ service runtime cycle.
+
+ * systemd-sysctl will now configure kernel parameters in the order
+ they occur in the configuration files. This matches what sysctl
+ has been traditionally doing.
+
+ * kernel-install "plugins" that are executed to perform various
+ tasks after a new kernel is added and before an old one is removed
+ can now return a special value to terminate the procedure and
+ prevent any later plugins from running.
+
+ * Journald's SplitMode=login setting has been deprecated. It has been
+ removed from documentation, and its use is discouraged. In a future
+ release it will be completely removed, and made equivalent to current
+ default of SplitMode=uid.
+
+ * Storage=both option setting in /etc/systemd/coredump.conf has been
+ removed. With fast LZ4 compression storing the core dump twice is not
+ useful.
+
+ * The --share-system systemd-nspawn option has been replaced with an
+ (undocumented) variable $SYSTEMD_NSPAWN_SHARE_SYSTEM, but the use of
+ this functionality is discouraged. In addition the variables
+ $SYSTEMD_NSPAWN_SHARE_NS_IPC, $SYSTEMD_NSPAWN_SHARE_NS_PID,
+ $SYSTEMD_NSPAWN_SHARE_NS_UTS may be used to control the unsharing of
+ individual namespaces.
+
+ * "machinectl list" now shows the IP address of running containers in
+ the output, as well as OS release information.
+
+ * "loginctl list" now shows the TTY of each session in the output.
+
+ * sd-bus gained new API calls sd_bus_track_set_recursive(),
+ sd_bus_track_get_recursive(), sd_bus_track_count_name(),
+ sd_bus_track_count_sender(). They permit usage of sd_bus_track peer
+ tracking objects in a "recursive" mode, where a single client can be
+ counted multiple times, if it takes multiple references.
+
+ * sd-bus gained new API calls sd_bus_set_exit_on_disconnect() and
+ sd_bus_get_exit_on_disconnect(). They may be used to to make a
+ process using sd-bus automatically exit if the bus connection is
+ severed.
+
+ * Bus clients of the service manager may now "pin" loaded units into
+ memory, by taking an explicit reference on them. This is useful to
+ ensure the client can retrieve runtime data about the service even
+ after the service completed execution. Taking such a reference is
+ available only for privileged clients and should be helpful to watch
+ running services in a race-free manner, and in particular collect
+ information about exit statuses and results.
+
+ * The nss-resolve module has been changed to strictly return UNAVAIL
+ when communication via D-Bus with resolved failed, and NOTFOUND when
+ a lookup completed but was negative. This means it is now possible to
+ neatly configure fallbacks using nsswitch.conf result checking
+ expressions. Taking benefit of this, the new recommended
+ configuration line for the "hosts" entry in /etc/nsswitch.conf is:
+
+ hosts: files mymachines resolve [!UNAVAIL=return] dns myhostname
+
+ * A new setting CtrlAltDelBurstAction= has been added to
+ /etc/systemd/system.conf which may be used to configure the precise
+ behaviour if the user on the console presses Ctrl-Alt-Del more often
+ than 7 times in 2s. Previously this would unconditionally result in
+ an expedited, immediate reboot. With this new setting the precise
+ operation may be configured in more detail, and also turned off
+ entirely.
+
+ * In .netdev files two new settings RemoteChecksumTx= and
+ RemoteChecksumRx= are now understood that permit configuring the
+ remote checksumming logic for VXLAN networks.
+
+ * The service manager learnt a new "invocation ID" concept for invoked
+ services. Each runtime cycle of a service will get a new invocation
+ ID (a 128bit random UUID) assigned that identifies the current
+ run of the service uniquely and globally. A new invocation ID
+ is generated each time a service starts up. The journal will store
+ the invocation ID of a service along with any logged messages, thus
+ making the invocation ID useful for matching the online runtime of a
+ service with the offline log data it generated in a safe way without
+ relying on synchronized timestamps. In many ways this new service
+ invocation ID concept is similar to the kernel's boot ID concept that
+ uniquely and globally identifies the runtime of each boot. The
+ invocation ID of a service is passed to the service itself via an
+ environment variable ($INVOCATION_ID). A new bus call
+ GetUnitByInvocationID() has been added that is similar to GetUnit()
+ but instead of retrieving the bus path for a unit by its name
+ retrieves it by its invocation ID. The returned path is valid only as
+ long as the passed invocation ID is current.
+
+ * systemd-resolved gained a new "DNSStubListener" setting in
+ resolved.conf. It either takes a boolean value or the special values
+ "udp" and "tcp", and configures whether to enable the stub DNS
+ listener on 127.0.0.53:53.
+
+ * IP addresses configured via networkd may now carry additional
+ configuration settings supported by the kernel. New options include:
+ HomeAddress=, DuplicateAddressDetection=, ManageTemporaryAddress=,
+ PrefixRoute=, AutoJoin=.
+
+ * The PAM configuration fragment file for "user@.service" shipped with
+ systemd (i.e. the --user instance of systemd) has been stripped to
+ the minimum necessary to make the system boot. Previously, it
+ contained Fedora-specific stanzas that did not apply to other
+ distributions. It is expected that downstream distributions add
+ additional configuration lines, matching their needs to this file,
+ using it only as rough template of what systemd itself needs. Note
+ that this reduced fragment does not even include an invocation of
+ pam_limits which most distributions probably want to add, even though
+ systemd itself does not need it. (There's also the new build time
+ option --with-pamconfdir=no to disable installation of the PAM
+ fragment entirely.)
+
+ * If PrivateDevices=yes is set for a service the CAP_SYS_RAWIO
+ capability is now also dropped from its set (in addition to
+ CAP_SYS_MKNOD as before).
+
+ * In service unit files it is now possible to connect a specific named
+ file descriptor with stdin/stdout/stdout of an executed service. The
+ name may be specified in matching .socket units using the
+ FileDescriptorName= setting.
+
+ * A number of journal settings may now be configured on the kernel
+ command line. Specifically, the following options are now understood:
+ systemd.journald.max_level_console=,
+ systemd.journald.max_level_store=,
+ systemd.journald.max_level_syslog=, systemd.journald.max_level_kmsg=,
+ systemd.journald.max_level_wall=.
+
+ * "systemctl is-enabled --full" will now show by which symlinks a unit
+ file is enabled in the unit dependency tree.
+
+ * Support for VeraCrypt encrypted partitions has been added to the
+ "cryptsetup" logic and /etc/crypttab.
+
+ * systemd-detect-virt gained support for a new --private-users switch
+ that checks whether the invoking processes are running inside a user
+ namespace. Similar, a new special value "private-users" for the
+ existing ConditionVirtualization= setting has been added, permitting
+ skipping of specific units in user namespace environments.
+
+ Contributions from: Alban Crequy, Alexander Kuleshov, Alfie John,
+ Andreas Henriksson, Andrew Jeddeloh, Balázs Úr, Bart Rulon, Benjamin
+ Richter, Ben Gamari, Ben Harris, Brian J. Murrell, Christian Brauner,
+ Christian Rebischke, Clinton Roy, Colin Walters, Cristian Rodríguez,
+ Daniel Hahler, Daniel Mack, Daniel Maixner, Daniel Rusek, Dan Dedrick,
+ Davide Cavalca, David Herrmann, David Michael, Dennis Wassenberg,
+ Djalal Harouni, Dongsu Park, Douglas Christman, Elias Probst, Eric
+ Cook, Erik Karlsson, Evgeny Vereshchagin, Felipe Sateler, Felix Zhang,
+ Franck Bui, George Hilliard, Giuseppe Scrivano, HATAYAMA Daisuke,
+ Heikki Kemppainen, Hendrik Brueckner, hi117, Ismo Puustinen, Ivan
+ Shapovalov, Jakub Filak, Jakub Wilk, Jan Synacek, Jason Kölker,
+ Jean-Sébastien Bour, Jiří Pírko, Jonathan Boulle, Jorge Niedbalski,
+ Keith Busch, kristbaum, Kyle Russell, Lans Zhang, Lennart Poettering,
+ Leonardo Brondani Schenkel, Lucas Werkmeister, Luca Bruno, Lukáš
+ Nykrýn, Maciek Borzecki, Mantas Mikulėnas, Marc-Antoine Perennou,
+ Marcel Holtmann, Marcos Mello, Martin Ejdestig, Martin Pitt, Matej
+ Habrnal, Maxime de Roucy, Michael Biebl, Michael Chapman, Michael Hoy,
+ Michael Olbrich, Michael Pope, Michal Sekletar, Michal Soltys, Mike
+ Gilbert, Nick Owens, Patrik Flykt, Paweł Szewczyk, Peter Hutterer,
+ Piotr Drąg, Reid Price, Richard W.M. Jones, Roman Stingler, Ronny
+ Chevalier, Seraphime Kirkovski, Stefan Schweter, Steve Muir, Susant
+ Sahani, Tejun Heo, Thomas Blume, Thomas H. P. Andersen, Tiago Levit,
+ Tobias Jungel, Tomáš Janoušek, Topi Miettinen, Torstein Husebø, Umut
+ Tezduyar Lindskog, Vito Caputo, WaLyong Cho, Wilhelm Schuster, Yann
+ E. MORIN, Yi EungJun, Yuki Inoguchi, Yu Watanabe, Zbigniew
+ Jędrzejewski-Szmek, Zeal Jagannatha
+
+ — Santa Fe, 2016-11-03
+
+CHANGES WITH 231:
+
+ * In service units the various ExecXYZ= settings have been extended
+ with an additional special character as first argument of the
+ assigned value: if the character '+' is used the specified command
+ line it will be run with full privileges, regardless of User=,
+ Group=, CapabilityBoundingSet= and similar options. The effect is
+ similar to the existing PermissionsStartOnly= option, but allows
+ configuration of this concept for each executed command line
+ independently.
+
+ * Services may now alter the service watchdog timeout at runtime by
+ sending a WATCHDOG_USEC= message via sd_notify().
+
+ * MemoryLimit= and related unit settings now optionally take percentage
+ specifications. The percentage is taken relative to the amount of
+ physical memory in the system (or in case of containers, the assigned
+ amount of memory). This allows scaling service resources neatly with
+ the amount of RAM available on the system. Similarly, systemd-logind's
+ RuntimeDirectorySize= option now also optionally takes percentage
+ values.
+
+ * In similar fashion TasksMax= takes percentage values now, too. The
+ value is taken relative to the configured maximum number of processes
+ on the system. The per-service task maximum has been changed to 15%
+ using this functionality. (Effectively this is an increase of 512 →
+ 4915 for service units, given the kernel's default pid_max setting.)
+
+ * Calendar time specifications in .timer units now understand a ".."
+ syntax for time ranges. Example: "4..7:10" may now be used for
+ defining a timer that is triggered at 4:10am, 5:10am, 6:10am and
+ 7:10am every day.
+
+ * The InaccessableDirectories=, ReadOnlyDirectories= and
+ ReadWriteDirectories= unit file settings have been renamed to
+ InaccessablePaths=, ReadOnlyPaths= and ReadWritePaths= and may now be
+ applied to all kinds of file nodes, and not just directories, with
+ the exception of symlinks. Specifically these settings may now be
+ used on block and character device nodes, UNIX sockets and FIFOS as
+ well as regular files. The old names of these settings remain
+ available for compatibility.
+
+ * systemd will now log about all service processes it kills forcibly
+ (using SIGKILL) because they remained after the clean shutdown phase
+ of the service completed. This should help identifying services that
+ shut down uncleanly. Moreover if KillUserProcesses= is enabled in
+ systemd-logind's configuration a similar log message is generated for
+ processes killed at the end of each session due to this setting.
+
+ * systemd will now set the $JOURNAL_STREAM environment variable for all
+ services whose stdout/stderr are connected to the Journal (which
+ effectively means by default: all services). The variable contains
+ the device and inode number of the file descriptor used for
+ stdout/stderr. This may be used by invoked programs to detect whether
+ their stdout/stderr is connected to the Journal, in which case they
+ can switch over to direct Journal communication, thus being able to
+ pass extended, structured metadata along with their log messages. As
+ one example, this is now used by glib's logging primitives.
+
+ * When using systemd's default tmp.mount unit for /tmp, the mount point
+ will now be established with the "nosuid" and "nodev" options. This
+ avoids privilege escalation attacks that put traps and exploits into
+ /tmp. However, this might cause problems if you e. g. put container
+ images or overlays into /tmp; if you need this, override tmp.mount's
+ "Options=" with a drop-in, or mount /tmp from /etc/fstab with your
+ desired options.
+
+ * systemd now supports the "memory" cgroup controller also on
+ cgroupsv2.
+
+ * The systemd-cgtop tool now optionally takes a control group path as
+ command line argument. If specified, the control group list shown is
+ limited to subgroups of that group.
+
+ * The SystemCallFilter= unit file setting gained support for
+ pre-defined, named system call filter sets. For example
+ SystemCallFilter=@clock is now an effective way to make all clock
+ changing-related system calls unavailable to a service. A number of
+ similar pre-defined groups are defined. Writing system call filters
+ for system services is simplified substantially with this new
+ concept. Accordingly, all of systemd's own, long-running services now
+ enable system call filtering based on this, by default.
+
+ * A new service setting MemoryDenyWriteExecute= has been added, taking
+ a boolean value. If turned on, a service may no longer create memory
+ mappings that are writable and executable at the same time. This
+ enhances security for services where this is enabled as it becomes
+ harder to dynamically write and then execute memory in exploited
+ service processes. This option has been enabled for all of systemd's
+ own long-running services.
+
+ * A new RestrictRealtime= service setting has been added, taking a
+ boolean argument. If set the service's processes may no longer
+ acquire realtime scheduling. This improves security as realtime
+ scheduling may otherwise be used to easily freeze the system.
+
+ * systemd-nspawn gained a new switch --notify-ready= taking a boolean
+ value. This may be used for requesting that the system manager inside
+ of the container reports start-up completion to nspawn which then
+ propagates this notification further to the service manager
+ supervising nspawn itself. A related option NotifyReady= in .nspawn
+ files has been added too. This functionality allows ordering of the
+ start-up of multiple containers using the usual systemd ordering
+ primitives.
+
+ * machinectl gained a new command "stop" that is an alias for
+ "terminate".
+
+ * systemd-resolved gained support for contacting DNS servers on
+ link-local IPv6 addresses.
+
+ * If systemd-resolved receives the SIGUSR2 signal it will now flush all
+ its caches. A method call for requesting the same operation has been
+ added to the bus API too, and is made available via "systemd-resolve
+ --flush-caches".
+
+ * systemd-resolve gained a new --status switch. If passed a brief
+ summary of the used DNS configuration with per-interface information
+ is shown.
+
+ * resolved.conf gained a new Cache= boolean option, defaulting to
+ on. If turned off local DNS caching is disabled. This comes with a
+ performance penalty in particular when DNSSEC is enabled. Note that
+ resolved disables its internal caching implicitly anyway, when the
+ configured DNS server is on a host-local IP address such as ::1 or
+ 127.0.0.1, thus automatically avoiding double local caching.
+
+ * systemd-resolved now listens on the local IP address 127.0.0.53:53
+ for DNS requests. This improves compatibility with local programs
+ that do not use the libc NSS or systemd-resolved's bus APIs for name
+ resolution. This minimal DNS service is only available to local
+ programs and does not implement the full DNS protocol, but enough to
+ cover local DNS clients. A new, static resolv.conf file, listing just
+ this DNS server is now shipped in /usr/lib/systemd/resolv.conf. It is
+ now recommended to make /etc/resolv.conf a symlink to this file in
+ order to route all DNS lookups to systemd-resolved, regardless if
+ done via NSS, the bus API or raw DNS packets. Note that this local
+ DNS service is not as fully featured as the libc NSS or
+ systemd-resolved's bus APIs. For example, as unicast DNS cannot be
+ used to deliver link-local address information (as this implies
+ sending a local interface index along), LLMNR/mDNS support via this
+ interface is severely restricted. It is thus strongly recommended for
+ all applications to use the libc NSS API or native systemd-resolved
+ bus API instead.
+
+ * systemd-networkd's bridge support learned a new setting
+ VLANFiltering= for controlling VLAN filtering. Moreover a new section
+ in .network files has been added for configuring VLAN bridging in
+ more detail: VLAN=, EgressUntagged=, PVID= in [BridgeVLAN].
+
+ * systemd-networkd's IPv6 Router Advertisement code now makes use of
+ the DNSSL and RDNSS options. This means IPv6 DNS configuration may
+ now be acquired without relying on DHCPv6. Two new options
+ UseDomains= and UseDNS= have been added to configure this behaviour.
+
+ * systemd-networkd's IPv6AcceptRouterAdvertisements= option has been
+ renamed IPv6AcceptRA=, without altering its behaviour. The old
+ setting name remains available for compatibility reasons.
+
+ * The systemd-networkd VTI/VTI6 tunneling support gained new options
+ Key=, InputKey= and OutputKey=.
+
+ * systemd-networkd gained support for VRF ("Virtual Routing Function")
+ interface configuration.
+
+ * "systemctl edit" may now be used to create new unit files by
+ specifying the --force switch.
+
+ * sd-event gained a new function sd_event_get_iteration() for
+ requesting the current iteration counter of the event loop. It starts
+ at zero and is increased by one with each event loop iteration.
+
+ * A new rpm macro %systemd_ordering is provided by the macros.systemd
+ file. It can be used in lieu of %systemd_requires in packages which
+ don't use any systemd functionality and are intended to be installed
+ in minimal containers without systemd present. This macro provides
+ ordering dependencies to ensure that if the package is installed in
+ the same rpm transaction as systemd, systemd will be installed before
+ the scriptlets for the package are executed, allowing unit presets
+ to be handled.
+
+ New macros %_systemdgeneratordir and %_systemdusergeneratordir have
+ been added to simplify packaging of generators.
+
+ * The os-release file gained VERSION_CODENAME field for the
+ distribution nickname (e.g. VERSION_CODENAME=woody).
+
+ * New udev property UDEV_DISABLE_PERSISTENT_STORAGE_RULES_FLAG=1
+ can be set to disable parsing of metadata and the creation
+ of persistent symlinks for that device.
+
+ * The v230 change to tag framebuffer devices (/dev/fb*) with "uaccess"
+ to make them available to logged-in users has been reverted.
+
+ * Much of the common code of the various systemd components is now
+ built into an internal shared library libsystemd-shared-231.so
+ (incorporating the systemd version number in the name, to be updated
+ with future releases) that the components link to. This should
+ decrease systemd footprint both in memory during runtime and on
+ disk. Note that the shared library is not for public use, and is
+ neither API not ABI stable, but is likely to change with every new
+ released update. Packagers need to make sure that binaries
+ linking to libsystemd-shared.so are updated in step with the
+ library.
+
+ * Configuration for "mkosi" is now part of the systemd
+ repository. mkosi is a tool to easily build legacy-free OS images,
+ and is available on github: https://github.com/systemd/mkosi. If
+ "mkosi" is invoked in the build tree a new raw OS image is generated
+ incorporating the systemd sources currently being worked on and a
+ clean, fresh distribution installation. The generated OS image may be
+ booted up with "systemd-nspawn -b -i", qemu-kvm or on any physical
+ UEFI PC. This functionality is particularly useful to easily test
+ local changes made to systemd in a pristine, defined environment. See
+ HACKING for details.
+
+ * configure learned the --with-support-url= option to specify the
+ distribution's bugtracker.
+
+ Contributions from: Alban Crequy, Alessandro Puccetti, Alessio Igor
+ Bogani, Alexander Kuleshov, Alexander Kurtz, Alex Gaynor, Andika
+ Triwidada, Andreas Pokorny, Andreas Rammhold, Andrew Jeddeloh, Ansgar
+ Burchardt, Atrotors, Benjamin Drung, Brian Boylston, Christian Hesse,
+ Christian Rebischke, Daniele Medri, Daniel Mack, Dave Reisner, David
+ Herrmann, David Michael, Djalal Harouni, Douglas Christman, Elias
+ Probst, Evgeny Vereshchagin, Federico Mena Quintero, Felipe Sateler,
+ Franck Bui, Harald Hoyer, Ian Lee, Ivan Shapovalov, Jakub Wilk, Jan
+ Janssen, Jean-Sébastien Bour, John Paul Adrian Glaubitz, Jouke
+ Witteveen, Kai Ruhnau, kpengboy, Kyle Walker, Lénaïc Huard, Lennart
+ Poettering, Luca Bruno, Lukas Lösche, Lukáš Nykrýn, mahkoh, Marcel
+ Holtmann, Martin Pitt, Marty Plummer, Matthieu Codron, Max Prokhorov,
+ Michael Biebl, Michael Karcher, Michael Olbrich, Michał Bartoszkiewicz,
+ Michal Sekletar, Michal Soltys, Minkyung, Muhammet Kara, mulkieran,
+ Otto Wallenius, Pablo Lezaeta Reyes, Peter Hutterer, Ronny Chevalier,
+ Rusty Bird, Stef Walter, Susant Sahani, Tejun Heo, Thomas Blume, Thomas
+ Haller, Thomas H. P. Andersen, Tobias Jungel, Tom Gundersen, Tom Yan,
+ Topi Miettinen, Torstein Husebø, Valentin Vidić, Viktar Vaŭčkievič,
+ WaLyong Cho, Weng Xuetian, Werner Fink, Zbigniew Jędrzejewski-Szmek
+
+ — Berlin, 2016-07-25
+
+CHANGES WITH 230:
+
+ * DNSSEC is now turned on by default in systemd-resolved (in
+ "allow-downgrade" mode), but may be turned off during compile time by
+ passing "--with-default-dnssec=no" to "configure" (and of course,
+ during runtime with DNSSEC= in resolved.conf). We recommend
+ downstreams to leave this on at least during development cycles and
+ report any issues with the DNSSEC logic upstream. We are very
+ interested in collecting feedback about the DNSSEC validator and its
+ limitations in the wild. Note however, that DNSSEC support is
+ probably nothing downstreams should turn on in stable distros just
+ yet, as it might create incompatibilities with a few DNS servers and
+ networks. We tried hard to make sure we downgrade to non-DNSSEC mode
+ automatically whenever we detect such incompatible setups, but there
+ might be systems we do not cover yet. Hence: please help us testing
+ the DNSSEC code, leave this on where you can, report back, but then
+ again don't consider turning this on in your stable, LTS or
+ production release just yet. (Note that you have to enable
+ nss-resolve in /etc/nsswitch.conf, to actually use systemd-resolved
+ and its DNSSEC mode for host name resolution from local
+ applications.)
+
+ * systemd-resolve conveniently resolves DANE records with the --tlsa
+ option and OPENPGPKEY records with the --openpgp option. It also
+ supports dumping raw DNS record data via the new --raw= switch.
+
+ * systemd-logind will now by default terminate user processes that are
+ part of the user session scope unit (session-XX.scope) when the user
+ logs out. This behavior is controlled by the KillUserProcesses=
+ setting in logind.conf, and the previous default of "no" is now
+ changed to "yes". This means that user sessions will be properly
+ cleaned up after, but additional steps are necessary to allow
+ intentionally long-running processes to survive logout.
+
+ While the user is logged in at least once, user@.service is running,
+ and any service that should survive the end of any individual login
+ session can be started at a user service or scope using systemd-run.
+ systemd-run(1) man page has been extended with an example which shows
+ how to run screen in a scope unit underneath user@.service. The same
+ command works for tmux.
+
+ After the user logs out of all sessions, user@.service will be
+ terminated too, by default, unless the user has "lingering" enabled.
+ To effectively allow users to run long-term tasks even if they are
+ logged out, lingering must be enabled for them. See loginctl(1) for
+ details. The default polkit policy was modified to allow users to
+ set lingering for themselves without authentication.
+
+ Previous defaults can be restored at compile time by the
+ --without-kill-user-processes option to "configure".
+
+ * systemd-logind gained new configuration settings SessionsMax= and
+ InhibitorsMax=, both with a default of 8192. It will not register new
+ user sessions or inhibitors above this limit.
+
+ * systemd-logind will now reload configuration on SIGHUP.
+
+ * The unified cgroup hierarchy added in Linux 4.5 is now supported.
+ Use systemd.unified_cgroup_hierarchy=1 on the kernel command line to
+ enable. Also, support for the "io" cgroup controller in the unified
+ hierarchy has been added, so that the "memory", "pids" and "io" are
+ now the controllers that are supported on the unified hierarchy.
+
+ WARNING: it is not possible to use previous systemd versions with
+ systemd.unified_cgroup_hierarchy=1 and the new kernel. Therefore it
+ is necessary to also update systemd in the initramfs if using the
+ unified hierarchy. An updated SELinux policy is also required.
+
+ * LLDP support has been extended, and both passive (receive-only) and
+ active (sender) modes are supported. Passive mode ("routers-only") is
+ enabled by default in systemd-networkd. Active LLDP mode is enabled
+ by default for containers on the internal network. The "networkctl
+ lldp" command may be used to list information gathered. "networkctl
+ status" will also show basic LLDP information on connected peers now.
+
+ * The IAID and DUID unique identifier sent in DHCP requests may now be
+ configured for the system and each .network file managed by
+ systemd-networkd using the DUIDType=, DUIDRawData=, IAID= options.
+
+ * systemd-networkd gained support for configuring proxy ARP support for
+ each interface, via the ProxyArp= setting in .network files. It also
+ gained support for configuring the multicast querier feature of
+ bridge devices, via the new MulticastQuerier= setting in .netdev
+ files. Similarly, snooping on the IGMP traffic can be controlled
+ via the new setting MulticastSnooping=.
+
+ A new setting PreferredLifetime= has been added for addresses
+ configured in .network file to configure the lifetime intended for an
+ address.
+
+ The systemd-networkd DHCP server gained the option EmitRouter=, which
+ defaults to yes, to configure whether the DHCP Option 3 (Router)
+ should be emitted.
+
+ * The testing tool /usr/lib/systemd/systemd-activate is renamed to
+ systemd-socket-activate and installed into /usr/bin. It is now fully
+ supported.
+
+ * systemd-journald now uses separate threads to flush changes to disk
+ when closing journal files, thus reducing impact of slow disk I/O on
+ logging performance.
+
+ * The sd-journal API gained two new calls
+ sd_journal_open_directory_fd() and sd_journal_open_files_fd() which
+ can be used to open journal files using file descriptors instead of
+ file or directory paths. sd_journal_open_container() has been
+ deprecated, sd_journal_open_directory_fd() should be used instead
+ with the flag SD_JOURNAL_OS_ROOT.
+
+ * journalctl learned a new output mode "-o short-unix" that outputs log
+ lines prefixed by their UNIX time (i.e. seconds since Jan 1st, 1970
+ UTC). It also gained support for a new --no-hostname setting to
+ suppress the hostname column in the family of "short" output modes.
+
+ * systemd-ask-password now optionally skips printing of the password to
+ stdout with --no-output which can be useful in scripts.
+
+ * Framebuffer devices (/dev/fb*) and 3D printers and scanners
+ (devices tagged with ID_MAKER_TOOL) are now tagged with
+ "uaccess" and are available to logged in users.
+
+ * The DeviceAllow= unit setting now supports specifiers (with "%").
+
+ * "systemctl show" gained a new --value switch, which allows print a
+ only the contents of a specific unit property, without also printing
+ the property's name. Similar support was added to "show*" verbs
+ of loginctl and machinectl that output "key=value" lists.
+
+ * A new unit type "generated" was added for files dynamically generated
+ by generator tools. Similarly, a new unit type "transient" is used
+ for unit files created using the runtime API. "systemctl enable" will
+ refuse to operate on such files.
+
+ * A new command "systemctl revert" has been added that may be used to
+ revert to the vendor version of a unit file, in case local changes
+ have been made by adding drop-ins or overriding the unit file.
+
+ * "machinectl clean" gained a new verb to automatically remove all or
+ just hidden container images.
+
+ * systemd-tmpfiles gained support for a new line type "e" for emptying
+ directories, if they exist, without creating them if they don't.
+
+ * systemd-nspawn gained support for automatically patching the UID/GIDs
+ of the owners and the ACLs of all files and directories in a
+ container tree to match the UID/GID user namespacing range selected
+ for the container invocation. This mode is enabled via the new
+ --private-users-chown switch. It also gained support for
+ automatically choosing a free, previously unused UID/GID range when
+ starting a container, via the new --private-users=pick setting (which
+ implies --private-users-chown). Together, these options for the first
+ time make user namespacing for nspawn containers fully automatic and
+ thus deployable. The systemd-nspawn@.service template unit file has
+ been changed to use this functionality by default.
+
+ * systemd-nspawn gained a new --network-zone= switch, that allows
+ creating ad-hoc virtual Ethernet links between multiple containers,
+ that only exist as long as at least one container referencing them is
+ running. This allows easy connecting of multiple containers with a
+ common link that implements an Ethernet broadcast domain. Each of
+ these network "zones" may be named relatively freely by the user, and
+ may be referenced by any number of containers, but each container may
+ only reference one of these "zones". On the lower level, this is
+ implemented by an automatically managed bridge network interface for
+ each zone, that is created when the first container referencing its
+ zone is created and removed when the last one referencing its zone
+ terminates.
+
+ * The default start timeout may now be configured on the kernel command
+ line via systemd.default_timeout_start_sec=. It was already
+ configurable via the DefaultTimeoutStartSec= option in
+ /etc/systemd/system.conf.
+
+ * Socket units gained a new TriggerLimitIntervalSec= and
+ TriggerLimitBurst= setting to configure a limit on the activation
+ rate of the socket unit.
+
+ * The LimitNICE= setting now optionally takes normal UNIX nice values
+ in addition to the raw integer limit value. If the specified
+ parameter is prefixed with "+" or "-" and is in the range -20..19 the
+ value is understood as UNIX nice value. If not prefixed like this it
+ is understood as raw RLIMIT_NICE limit.
+
+ * Note that the effect of the PrivateDevices= unit file setting changed
+ slightly with this release: the per-device /dev file system will be
+ mounted read-only from this version on, and will have "noexec"
+ set. This (minor) change of behavior might cause some (exceptional)
+ legacy software to break, when PrivateDevices=yes is set for its
+ service. Please leave PrivateDevices= off if you run into problems
+ with this.
+
+ * systemd-bootchart has been split out to a separate repository:
+ https://github.com/systemd/systemd-bootchart
+
+ * systemd-bus-proxyd has been removed, as kdbus is unlikely to still be
+ merged into the kernel in its current form.
+
+ * The compatibility libraries libsystemd-daemon.so,
+ libsystemd-journal.so, libsystemd-id128.so, and libsystemd-login.so
+ which have been deprecated since systemd-209 have been removed along
+ with the corresponding pkg-config files. All symbols provided by
+ those libraries are provided by libsystemd.so.
+
+ * The Capabilities= unit file setting has been removed (it is ignored
+ for backwards compatibility). AmbientCapabilities= and
+ CapabilityBoundingSet= should be used instead.
+
+ * A new special target has been added, initrd-root-device.target,
+ which creates a synchronization point for dependencies of the root
+ device in early userspace. Initramfs builders must ensure that this
+ target is now included in early userspace.
+
+ Contributions from: Alban Crequy, Alexander Kuleshov, Alexander Shopov,
+ Alex Crawford, Andre Klärner, Andrew Eikum, Beniamino Galvani, Benjamin
+ Robin, Biao Lu, Bjørnar Ness, Calvin Owens, Christian Hesse, Clemens
+ Gruber, Colin Guthrie, Daniel Drake, Daniele Medri, Daniel J Walsh,
+ Daniel Mack, Dan Nicholson, daurnimator, David Herrmann, David
+ R. Hedges, Elias Probst, Emmanuel Gil Peyrot, EMOziko, Evgeny
+ Vereshchagin, Federico, Felipe Sateler, Filipe Brandenburger, Franck
+ Bui, frankheckenbach, gdamjan, Georgia Brikis, Harald Hoyer, Hendrik
+ Brueckner, Hristo Venev, Iago López Galeiras, Ian Kelling, Ismo
+ Puustinen, Jakub Wilk, Jaroslav Škarvada, Jeff Huang, Joel Holdsworth,
+ John Paul Adrian Glaubitz, Jonathan Boulle, kayrus, Klearchos
+ Chaloulos, Kyle Russell, Lars Uebernickel, Lennart Poettering, Lubomir
+ Rintel, Lukáš Nykrýn, Mantas Mikulėnas, Marcel Holtmann, Martin Pitt,
+ Michael Biebl, michaelolbrich, Michał Bartoszkiewicz, Michal Koutný,
+ Michal Sekletar, Mike Frysinger, Mike Gilbert, Mingcong Bai, Ming Lin,
+ mulkieran, muzena, Nalin Dahyabhai, Naohiro Aota, Nathan McSween,
+ Nicolas Braud-Santoni, Patrik Flykt, Peter Hutterer, Peter Mattern,
+ Petr Lautrbach, Petros Angelatos, Piotr Drąg, Rabin Vincent, Robert
+ Węcławski, Ronny Chevalier, Samuel Tardieu, Stefan Saraev, Stefan
+ Schallenberg aka nafets227, Steven Siloti, Susant Sahani, Sylvain
+ Plantefève, Taylor Smock, Tejun Heo, Thomas Blume, Thomas Haller,
+ Thomas H. P. Andersen, Tobias Klauser, Tom Gundersen, topimiettinen,
+ Torstein Husebø, Umut Tezduyar Lindskog, Uwe Kleine-König, Victor Toso,
+ Vinay Kulkarni, Vito Caputo, Vittorio G (VittGam), Vladimir Panteleev,
+ Wieland Hoffmann, Wouter Verhelst, Yu Watanabe, Zbigniew
+ Jędrzejewski-Szmek
+
+ — Fairfax, 2016-05-21
+
+CHANGES WITH 229:
+
+ * The systemd-resolved DNS resolver service has gained a substantial
+ set of new features, most prominently it may now act as a DNSSEC
+ validating stub resolver. DNSSEC mode is currently turned off by
+ default, but is expected to be turned on by default in one of the
+ next releases. For now, we invite everybody to test the DNSSEC logic
+ by setting DNSSEC=allow-downgrade in /etc/systemd/resolved.conf. The
+ service also gained a full set of D-Bus interfaces, including calls
+ to configure DNS and DNSSEC settings per link (for use by external
+ network management software). systemd-resolved and systemd-networkd
+ now distinguish between "search" and "routing" domains. The former
+ are used to qualify single-label names, the latter are used purely
+ for routing lookups within certain domains to specific links.
+ resolved now also synthesizes RRs for all entries from /etc/hosts.
+
+ * The systemd-resolve tool (which is a client utility for
+ systemd-resolved) has been improved considerably and is now fully
+ supported and documented. Hence it has moved from /usr/lib/systemd to
+ /usr/bin.
+
+ * /dev/disk/by-path/ symlink support has been (re-)added for virtio
+ devices.
+
+ * The coredump collection logic has been reworked: when a coredump is
+ collected it is now written to disk, compressed and processed
+ (including stacktrace extraction) from a new instantiated service
+ systemd-coredump@.service, instead of directly from the
+ /proc/sys/kernel/core_pattern hook we provide. This is beneficial as
+ processing large coredumps can take up a substantial amount of
+ resources and time, and this previously happened entirely outside of
+ systemd's service supervision. With the new logic the core_pattern
+ hook only does minimal metadata collection before passing off control
+ to the new instantiated service, which is configured with a time
+ limit, a nice level and other settings to minimize negative impact on
+ the rest of the system. Also note that the new logic will honour the
+ RLIMIT_CORE setting of the crashed process, which now allows users
+ and processes to turn off coredumping for their processes by setting
+ this limit.
+
+ * The RLIMIT_CORE resource limit now defaults to "unlimited" for PID 1
+ and all forked processes by default. Previously, PID 1 would leave
+ the setting at "0" for all processes, as set by the kernel. Note that
+ the resource limit traditionally has no effect on the generated
+ coredumps on the system if the /proc/sys/kernel/core_pattern hook
+ logic is used. Since the limit is now honoured (see above) its
+ default has been changed so that the coredumping logic is enabled by
+ default for all processes, while allowing specific opt-out.
+
+ * When the stacktrace is extracted from processes of system users, this
+ is now done as "systemd-coredump" user, in order to sandbox this
+ potentially security sensitive parsing operation. (Note that when
+ processing coredumps of normal users this is done under the user ID
+ of process that crashed, as before.) Packagers should take notice
+ that it is now necessary to create the "systemd-coredump" system user
+ and group at package installation time.
+
+ * The systemd-activate socket activation testing tool gained support
+ for SOCK_DGRAM and SOCK_SEQPACKET sockets using the new --datagram
+ and --seqpacket switches. It also has been extended to support both
+ new-style and inetd-style file descriptor passing. Use the new
+ --inetd switch to request inetd-style file descriptor passing.
+
+ * Most systemd tools now honor a new $SYSTEMD_COLORS environment
+ variable, which takes a boolean value. If set to false, ANSI color
+ output is disabled in the tools even when run on a terminal that
+ supports it.
+
+ * The VXLAN support in networkd now supports two new settings
+ DestinationPort= and PortRange=.
+
+ * A new systemd.machine_id= kernel command line switch has been added,
+ that may be used to set the machine ID in /etc/machine-id if it is
+ not initialized yet. This command line option has no effect if the
+ file is already initialized.
+
+ * systemd-nspawn gained a new --as-pid2 switch that invokes any
+ specified command line as PID 2 rather than PID 1 in the
+ container. In this mode PID 1 is a minimal stub init process that
+ implements the special POSIX and Linux semantics of PID 1 regarding
+ signal and child process management. Note that this stub init process
+ is implemented in nspawn itself and requires no support from the
+ container image. This new logic is useful to support running
+ arbitrary commands in the container, as normal processes are
+ generally not prepared to run as PID 1.
+
+ * systemd-nspawn gained a new --chdir= switch for setting the current
+ working directory for the process started in the container.
+
+ * "journalctl /dev/sda" will now output all kernel log messages for
+ specified device from the current boot, in addition to all devices
+ that are parents of it. This should make log output about devices
+ pretty useful, as long as kernel drivers attach enough metadata to
+ the log messages. (The usual SATA drivers do.)
+
+ * The sd-journal API gained two new calls
+ sd_journal_has_runtime_files() and sd_journal_has_persistent_files()
+ that report whether log data from /run or /var has been found.
+
+ * journalctl gained a new switch "--fields" that prints all journal
+ record field names currently in use in the journal. This is backed
+ by two new sd-journal API calls sd_journal_enumerate_fields() and
+ sd_journal_restart_fields().
+
+ * Most configurable timeouts in systemd now expect an argument of
+ "infinity" to turn them off, instead of "0" as before. The semantics
+ from now on is that a timeout of "0" means "now", and "infinity"
+ means "never". To maintain backwards compatibility, "0" continues to
+ turn off previously existing timeout settings.
+
+ * "systemctl reload-or-try-restart" has been renamed to "systemctl
+ try-reload-or-restart" to clarify what it actually does: the "try"
+ logic applies to both reloading and restarting, not just restarting.
+ The old name continues to be accepted for compatibility.
+
+ * On boot-up, when PID 1 detects that the system clock is behind the
+ release date of the systemd version in use, the clock is now set
+ to the latter. Previously, this was already done in timesyncd, in order
+ to avoid running with clocks set to the various clock epochs such as
+ 1902, 1938 or 1970. With this change the logic is now done in PID 1
+ in addition to timesyncd during early boot-up, so that it is enforced
+ before the first process is spawned by systemd. Note that the logic
+ in timesyncd remains, as it is more comprehensive and ensures
+ clock monotonicity by maintaining a persistent timestamp file in
+ /var. Since /var is generally not available in earliest boot or the
+ initrd, this part of the logic remains in timesyncd, and is not done
+ by PID 1.
+
+ * Support for tweaking details in net_cls.class_id through the
+ NetClass= configuration directive has been removed, as the kernel
+ people have decided to deprecate that controller in cgroup v2.
+ Userspace tools such as nftables are moving over to setting rules
+ that are specific to the full cgroup path of a task, which obsoletes
+ these controllers anyway. The NetClass= directive is kept around for
+ legacy compatibility reasons. For a more in-depth description of the
+ kernel change, please refer to the respective upstream commit:
+
+ https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bd1060a1d671
+
+ * A new service setting RuntimeMaxSec= has been added that may be used
+ to specify a maximum runtime for a service. If the timeout is hit, the
+ service is terminated and put into a failure state.
+
+ * A new service setting AmbientCapabilities= has been added. It allows
+ configuration of additional Linux process capabilities that are
+ passed to the activated processes. This is only available on very
+ recent kernels.
+
+ * The process resource limit settings in service units may now be used
+ to configure hard and soft limits individually.
+
+ * The various libsystemd APIs such as sd-bus or sd-event now publicly
+ expose support for gcc's __attribute__((cleanup())) C extension.
+ Specifically, for many object destructor functions alternative
+ versions have been added that have names suffixed with "p" and take a
+ pointer to a pointer to the object to destroy, instead of just a
+ pointer to the object itself. This is useful because these destructor
+ functions may be used directly as parameters to the cleanup
+ construct. Internally, systemd has been a heavy user of this GCC
+ extension for a long time, and with this change similar support is
+ now available to consumers of the library outside of systemd. Note
+ that by using this extension in your sources compatibility with old
+ and strictly ANSI compatible C compilers is lost. However, all gcc or
+ LLVM versions of recent years support this extension.
+
+ * Timer units gained support for a new setting RandomizedDelaySec= that
+ allows configuring some additional randomized delay to the configured
+ time. This is useful to spread out timer events to avoid load peaks in
+ clusters or larger setups.
+
+ * Calendar time specifications now support sub-second accuracy.
+
+ * Socket units now support listening on SCTP and UDP-lite protocol
+ sockets.
+
+ * The sd-event API now comes with a full set of man pages.
+
+ * Older versions of systemd contained experimental support for
+ compressing journal files and coredumps with the LZ4 compressor that
+ was not compatible with the lz4 binary (due to API limitations of the
+ lz4 library). This support has been removed; only support for files
+ compatible with the lz4 binary remains. This LZ4 logic is now
+ officially supported and no longer considered experimental.
+
+ * The dkr image import logic has been removed again from importd. dkr's
+ micro-services focus doesn't fit into the machine image focus of
+ importd, and quickly got out of date with the upstream dkr API.
+
+ * Creation of the /run/lock/lockdev/ directory was dropped from
+ tmpfiles.d/legacy.conf. Better locking mechanisms like flock() have
+ been available for many years. If you still need this, you need to
+ create your own tmpfiles.d config file with:
+
+ d /run/lock/lockdev 0775 root lock -
+
+ Contributions from: Abdo Roig-Maranges, Alban Crequy, Aleksander
+ Adamowski, Alexander Kuleshov, Andreas Pokorny, Andrei Borzenkov,
+ Andrew Wilcox, Arthur Clement, Beniamino Galvani, Casey Schaufler,
+ Chris Atkinson, Chris Mayo, Christian Hesse, Damjan Georgievski, Dan
+ Dedrick, Daniele Medri, Daniel J Walsh, Daniel Korostil, Daniel Mack,
+ David Herrmann, Dimitri John Ledkov, Dominik Hannen, Douglas Christman,
+ Evgeny Vereshchagin, Filipe Brandenburger, Franck Bui, Gabor Kelemen,
+ Harald Hoyer, Hayden Walles, Helmut Grohne, Henrik Kaare Poulsen,
+ Hristo Venev, Hui Wang, Indrajit Raychaudhuri, Ismo Puustinen, Jakub
+ Wilk, Jan Alexander Steffens (heftig), Jan Engelhardt, Jan Synacek,
+ Joost Bremmer, Jorgen Schaefer, Karel Zak, Klearchos Chaloulos,
+ lc85446, Lennart Poettering, Lukas Nykryn, Mantas Mikulėnas, Marcel
+ Holtmann, Martin Pitt, Michael Biebl, Michael Olbrich, Michael Scherer,
+ Michał Górny, Michal Sekletar, Nicolas Cornu, Nicolas Iooss, Nils
+ Carlson, nmartensen, nnz1024, Patrick Ohly, Peter Hutterer, Phillip Sz,
+ Ronny Chevalier, Samu Kallio, Shawn Landden, Stef Walter, Susant
+ Sahani, Sylvain Plantefève, Tadej Janež, Thomas Hindoe Paaboel
+ Andersen, Tom Gundersen, Torstein Husebø, Umut Tezduyar Lindskog, Vito
+ Caputo, WaLyong Cho, Yu Watanabe, Zbigniew Jędrzejewski-Szmek
+
+ — Berlin, 2016-02-11
+