Systemd 246 Released With Many Changes

Systemd 246 is out today as the newest version of this dominant Linux init system and system/service manager. Systemd 246 has a lot of new functionality in time for making it into at least some of the autumn 2020 Linux distributions.

Among the many changes to find with systemd 246 are:

- Systemd-journald now supports Zstd compression of journal files. Similarly, coredumps collected by systemd-coredump can now make use of Zstd compression.

- Tmpfs mounts automatically created by systemd such as for /tmp and /run whill now have a limit of 50% of RAM for /tmp and /dev/sdm while 10% of RAM for other mounts.

- The systemd-homed LUKS back-end can now automatically discard empty system blocks when a user logs out.

- Systemd-homed also now better protects against potential double data encryption scenarios. Systemd-homed can also support unlocking home directories using FIOD2 security tokens.

- Systemd-cryptsetup can now activate Microsoft BitLocker volumes during boot.

- A new systemd-xdg-autostart-generator command for generating systemd unit files from XDG autostart .desktop files.

- A change from Microsoft that will now expose some host OS information to containers.

- The system hostname can now be set at boot time with the systemd.hostname= kernel option. There are also other new kernel command line options like systemd.swap= for toggling if SWAP is enabled and systemd.clock-usec= for specifying the Unix time at boot.

- Systemd has begun a new hardware database file that is collecting information on PCI and USB devices that correctly auto-suspend. This database is initially based on data from ChromeOS/ChromiumOS.

- A number of systemd-networkd improvements. Similarly, systemd-resolved saw a number of improvements including SNI validation for its DNS-over-TLS support.

- New settings like ConditionPathIsEncrypted, AssertPathIsEncrypted, ConditionEnvironment, AssertEnvironment, RootHash / RootHashSignature, TimeoutStartFailureMode/TimeoutStopFailureMode, and CoredumpFilter.

- Systemd will warn of processes leftover in a unit after that unit has stopped.

- The CPU affinity setting in systemd service unit files can now be set to "numa" so their mask is set based on the NUMA mask.

- Basic support for the cgroup v2 freezer.

- PID1 can automatically load pre-compiled AppArmor policies during early boot.

More details on all of the systemd 246 changes via the NEWS file. Those building systemd from source can find it via GitHub.