%general-entities; ]> Systemd Customization The /etc/systemd/system.conf file contains a set of options to control basic systemd operations. The default file has all entries commented out with the default settings indicated. This file is where the log level may be changed as well as some basic logging settings. See systemd-system.conf(5) manual page for details on each configuration option. The normal behavior for systemd is to clear the screen at the end of the boot sequence. If desired, this behavior may be changed by running the following command: mkdir -pv /etc/systemd/system/getty@tty1.service.d cat > /etc/systemd/system/getty@tty1.service.d/noclear.conf << EOF [Service] TTYVTDisallocate=no EOF The boot messages can always be revied by using the journalctl -b command as the root user. By default, /tmp is created as a tmpfs. If this is not desired, it can be overridden by the following: ln -sfv /dev/null /etc/systemd/system/tmp.mount This is not necessary if there is a separate partition for /tmp specified in /etc/fstab. There are several services that create or delete files or directories: systemd-tmpfiles-clean.service systemd-tmpfiles-setup-dev.service systemd-tmpfiles-setup.service The system location for the configuration files is /usr/lib/tmpfiles.d/*.conf. The local configuration files are in /etc/tmpfiles.d. Files in /etc/tmpfiles.d override files with the same name in /usr/lib/tmpfiles.d. See tmpfiles.d(5) manual page for file format details. The parameter of a unit can be overriden by creating a directory and a configuration file in /etc/systemd/system. For example: mkdir -pv /etc/systemd/system/foobar.service.d cat > /etc/systemd/system/foobar.service.d/foobar.conf << EOF [Service] Restart=always RestartSec=30 EOF See systemd.unit(5) manual page for more information. After creating the configuration file, run systemctl daemon-reload and systemctl restart foobar to activate the changes to a service. Rather than plain shell scripts used in SysVinit or BSD style init systems, systemd uses a unified format for different types of startup files (or units). The command systemctl is used to enable, disable, controll state, and obtain status of unit files. Here are some examples of frequently used commands: systemctl list-units -t <service> [--all]: lists loaded unit files of type service. systemctl list-units -t <target> [--all]: lists loaded unit files of type target. systemctl show -p Wants <multi-user.target>: shows all units that depend on the multi-user target. Targets are special unit files that are anogalous to runlevels under SysVinit. systemctl status <servicename.service>: shows the status of the servicename service. The .service extension can be omitted if there are no other unit files with the same name, such as .socket files (which create a listening socket that provides similar functionality to inetd/xinetd). Logging on a system booted with systemd is handled with systemd-journald (by default), rather than a typical unix syslog daemon. You can also add a normal syslog daemon and have both work side by side if desired. The systemd-journald program stores journal entries in a binary format rather than a plain text log file. To assist with parsing the file, the command journalctl is provided. Here are some examples of frequently used commands: journalctl -r: shows all contents of the journal in reverse chronological order. journalctl -u UNIT: shows the journal entries associated with the specified UNIT file. journalctl -b[=ID] -r: shows the journal entries since last successfull boot (or for boot ID) in reverse chronological order. journalctl -f: povides functionality similar to tail -f (follow).