systemd System and Service Manager
+CHANGES WITH 230 in spe:
+
+ * 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 incompabilities 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.
+
+ * Testing tool /usr/lib/systemd/systemd-activate is renamed to
+ systemd-socket-activate and installed into /usr/bin. It is now fully
+ supported.
+
+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
+
CHANGES WITH 228:
* A number of properties previously only settable in unit