X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.xml;h=bf7a7a6f67209c7dc4384d1e3c9af46ef1b191b4;hp=007705e4943ebaa296505c8e2195d2834be4747c;hb=f280bcfb21aacce03abf17b3ad732c1351df42b9;hpb=99ffae46d38f05b6c8bc09fe29e50a507ae8b79b diff --git a/man/systemd.xml b/man/systemd.xml index 007705e49..bf7a7a6f6 100644 --- a/man/systemd.xml +++ b/man/systemd.xml @@ -8,20 +8,21 @@ Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU General Public License + You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . --> - + systemd @@ -45,7 +46,7 @@ systemd init - systemd System and Session Manager + systemd system and service manager @@ -60,7 +61,7 @@ Description - systemd is a system and session manager for + systemd is a system and service manager for Linux operating systems. When run as first process on boot (as PID 1), it acts as init system that brings up and maintains userspace services. @@ -73,6 +74,13 @@ are mostly equivalent when invoked from normal login sessions. See telinit8 for more information. + + When run as system instance, systemd interprets + the configuration file + system.conf, otherwise + user.conf. See + systemd-system.conf5 + for more information. @@ -82,76 +90,106 @@ - - + + + Determine startup + sequence, dump it and exit. This is an + option useful for debugging + only. + + + - Prints a short help - text and exits. + Dump understood unit + configuration items. This outputs a + terse but complete list of + configuration items understood in unit + definition files. Set default unit to - activate on startup. If not specified + activate on startup. If not specified, defaults to default.target. - - - Tell systemd to run in - a particular mode. Argument is one of - , - . Normally it - should not be necessary to pass this - option, as systemd automatically - detects the mode it is started - in. This call is hence of little use - except for - debugging. + + + + For , + tell systemd to run a + system instance, even if the process ID is + not 1, i.e. systemd is not run as init process. + does the opposite, + running a user instance even if the process + ID is 1. + Normally it should not be necessary to + pass these options, as systemd + automatically detects the mode it is + started in. These options are hence of + little use except for debugging. Note + that it is not supported booting and + maintaining a full system with systemd + running in + mode, but PID not 1. In practice, + passing explicitly is + only useful in conjunction with + . - + - Determine startup - sequence, dump it and exit. This is an - option useful for debugging - only. + Dump core on + crash. This switch has no effect when + run as user + instance. - + - Dump understood unit - configuration items. This outputs a - terse but complete list of - configuration items understood in unit - definition files. + Run shell on + crash. This switch has no effect when + run as user + instance. - Ask for confirmation when spawning processes. + Ask for confirmation + when spawning processes. This switch + has no effect when run as user + instance. + + + + + Show terse service + status information while booting. This + switch has no effect when run as user + instance. Takes a boolean argument + which may be omitted which is + interpreted as + . - + - Extract D-Bus - interface introspection data. This is - mostly useful at build at install time - to generate data suitable for the - D-Bus interfaces - repository. Optionally the interface - name for the introspection data may be - specified. If omitted, the - introspection data for all interfaces - is dumped. + Set log + target. Argument must be one of + , + , + , + , + . Set log level. As argument this accepts a numerical log - level or the well-known syslog3 + level or the well-known syslog3 symbolic names (lowercase): , , @@ -162,23 +200,12 @@ , . - - - - Set log - target. Argument must be one of - , - , - , - , - . - Highlight important log messages. Argument is a boolean - value. If the argument is omitted it + value. If the argument is omitted, it defaults to . @@ -193,6 +220,39 @@ it defaults to . + + + + + Sets the default + output or error output for all + services and sockets, respectively. That is, controls + the default for + + and + (see + systemd.exec5 + for details). Takes one of + , + , + , + , + , + , + , + , + . If the + argument is omitted + + defaults to + and + + to + . + + + + @@ -200,23 +260,36 @@ Concepts systemd provides a dependency system between - various entities called "units". Units encapsulate - various objects that are relevant for system boot-up - and maintainance. The majority of units are configured - in unit configuration files, whose syntax and basic - set of options is described in + various entities called "units" of 12 different + types. Units encapsulate various objects that are + relevant for system boot-up and maintenance. The + majority of units are configured in unit configuration + files, whose syntax and basic set of options is + described in systemd.unit5, however some are created automatically from other - configuration or dynamically from system state. Units - may be active (meaning started, bound, plugged in, ... - depending on the unit type), or inactive (meaning - stopped, unbound, unplugged, ...), as well is in the + configuration, dynamically from system state or + programmatically at runtime. Units may be "active" + (meaning started, bound, plugged in, ..., depending on + the unit type, see below), or "inactive" (meaning + stopped, unbound, unplugged, ...), as well as in the process of being activated or deactivated, - i.e. between the two states. The following unit types - are available: + i.e. between the two states (these states are called + "activating", "deactivating"). A special "failed" + state is available as well, which is very similar to + "inactive" and is entered when the service failed in + some way (process returned error code on exit, or + crashed, or an operation timed out). If this state is + entered, the cause will be logged, for later + reference. Note that the various unit types may have a + number of additional substates, which are mapped to + the five generalized unit states described + here. + + The following unit types are available: - Service units, which control + Service units, which start and control daemons and the processes they consist of. For details see systemd.service5. @@ -256,7 +329,7 @@ systemd units, which later may be restored by activating the saved snapshot unit. For more information see - systemd.automount5. + systemd.snapshot5. Timer units are useful for triggering activation of other units based on @@ -264,24 +337,65 @@ systemd.timer5. Swap units are very similar to - mount units and encapsulated memory swap + mount units and encapsulate memory swap partitions or files of the operating - systemd. They are described in systemd.swap5. + system. They are described in systemd.swap5. Path units may be used - activate other services when file system + to activate other services when file system objects change or are modified. See systemd.path5. + Slice units may be used to + group units which manage system processes + (such as service and scope units) in a + hierarchical tree for resource management + purposes. See + systemd.slice5. + + Scope units are similar to + service units, but manage foreign processes + instead of starting them as well. See + systemd.scope5. + Units are named as their configuration files. Some units have special semantics. A detailed - list you may find in + list is available in systemd.special7. + systemd knows various kinds of dependencies, + including positive and negative requirement + dependencies (i.e. Requires= and + Conflicts=) as well as ordering + dependencies (After= and + Before=). NB: ordering and + requirement dependencies are orthogonal. If only a + requirement dependency exists between two units + (e.g. foo.service requires + bar.service), but no ordering + dependency (e.g. foo.service + after bar.service) and both are + requested to start, they will be started in + parallel. It is a common pattern that both requirement + and ordering dependencies are placed between two + units. Also note that the majority of dependencies are + implicitly created and maintained by systemd. In most + cases, it should be unnecessary to declare additional + dependencies manually, however it is possible to do + this. + + Application programs and units (via + dependencies) may request state changes of units. In + systemd, these requests are encapsulated as 'jobs' and + maintained in a job queue. Jobs may succeed or can + fail, their execution is ordered based on the ordering + dependencies of the units they have been scheduled + for. + On boot systemd activates the target unit - default.target whose job it is to + default.target whose job is to activate on-boot services and other on-boot units by pulling them in via dependencies. Usually the unit name is just an alias (symlink) for either @@ -290,16 +404,94 @@ multi-user.target (for limited console-only boots for use in embedded or server environments, or similar; a subset of - graphical.target). However it is at the discretion of + graphical.target). However, it is at the discretion of the administrator to configure it as an alias to any other target unit. See systemd.special7 for details about these target units. + Processes systemd spawns are placed in + individual Linux control groups named after the unit + which they belong to in the private systemd + hierarchy. (see cgroups.txt + for more information about control groups, or short + "cgroups"). systemd uses this to effectively keep + track of processes. Control group information is + maintained in the kernel, and is accessible via the + file system hierarchy (beneath + /sys/fs/cgroup/systemd/), or in tools + such as + ps1 + (ps xawf -eo pid,user,cgroup,args + is particularly useful to list all processes and the + systemd units they belong to.). + + systemd is compatible with the SysV init system + to a large degree: SysV init scripts are supported and + simply read as an alternative (though limited) + configuration file format. The SysV + /dev/initctl interface is + provided, and compatibility implementations of the + various SysV client tools are available. In addition to + that, various established Unix functionality such as + /etc/fstab or the + utmp database are + supported. + + systemd has a minimal transaction system: if a + unit is requested to start up or shut down it will add + it and all its dependencies to a temporary + transaction. Then, it will verify if the transaction + is consistent (i.e. whether the ordering of all units + is cycle-free). If it is not, systemd will try to fix + it up, and removes non-essential jobs from the + transaction that might remove the loop. Also, systemd + tries to suppress non-essential jobs in the + transaction that would stop a running service. Finally + it is checked whether the jobs of the transaction + contradict jobs that have already been queued, and + optionally the transaction is aborted then. If all + worked out and the transaction is consistent and + minimized in its impact it is merged with all already + outstanding jobs and added to the run + queue. Effectively this means that before executing a + requested operation, systemd will verify that it makes + sense, fixing it if possible, and only failing if it + really cannot work. + + Systemd contains native implementations of + various tasks that need to be executed as part of the + boot process. For example, it sets the hostname or + configures the loopback network device. It also sets + up and mounts various API file systems, such as + /sys or + /proc. + For more information about the concepts and - ideas behind systemd please refer to the Original - Announcement Document. + Design Document. + + Note that some but not all interfaces provided + by systemd are covered by the Interface + Stability Promise. + + Units may be generated dynamically at boot and + system manager reload time, for example based on other + configuration files or parameters passed on the kernel + command line. For details see the Generators + Specification. + + Systems which invoke systemd in a container + or initrd environment should implement the + Container + Interface or initrd + Interface specifications, respectively. @@ -317,28 +509,33 @@ pkg-config systemd --variable=systemdsystemunitdir. Other directories checked are - /usr/local/share/systemd/system + /usr/local/lib/systemd/system and - /usr/share/systemd/system. User + /usr/lib/systemd/system. User configuration always takes precedence. pkg-config systemd --variable=systemdsystemconfdir returns the path of the system configuration directory. Packages - should alter the content of these directories - only with the - systemd-install1 - tool. + should alter the content of these + directories only with the + enable and + disable commands of + the + systemctl1 + tool. Full list of directories is provided in + systemd.unit5. + - Session unit directories + User unit directories Similar rules apply - for the session unit + for the user unit directories. However, here the XDG Base Directory specification @@ -346,16 +543,21 @@ units. Applications should place their unit files in the directory returned by pkg-config systemd - --variable=systemdsessionunitdir. Global - configuration is done in the - directory reported by - pkg-config systemd - --variable=systemdsessionconfdir. The - systemd-install1 + --variable=systemduserunitdir. Global + configuration is done in the directory + reported by pkg-config + systemd + --variable=systemduserconfdir. The + enable and + disable commands of + the + systemctl1 tool can handle both global (i.e. for all users) and private (for one user) enabling/disabling of - units. + units. Full list of directories is provided in + systemd.unit5. + @@ -386,7 +588,7 @@ when figuring out whether a service shall be enabled. Note that a service unit with a native unit configuration - file can be started by activating it + file cannot be started by activating it in the SysV runlevel link farm. @@ -398,7 +600,7 @@ - SIGTERM + SIGTERM Upon receiving this signal the systemd system manager @@ -408,17 +610,17 @@ to systemctl daemon-reexec. - systemd session managers will + systemd user managers will start the exit.target unit when this signal is received. This is mostly equivalent to - systemctl --session start + systemctl --user start exit.target. - SIGINT + SIGINT Upon receiving this signal the systemd system manager will @@ -428,13 +630,13 @@ systemctl start ctl-alt-del.target. - systemd session managers + systemd user managers treat this signal the same way as - SIGTERM. + SIGTERM. - SIGWINCH + SIGWINCH When this signal is received the systemd system manager @@ -445,12 +647,12 @@ kbrequest.target. This signal is ignored by - systemd session + systemd user managers. - SIGPWR + SIGPWR When this signal is received the systemd manager @@ -462,7 +664,7 @@ - SIGUSR1 + SIGUSR1 When this signal is received the systemd manager will try @@ -471,7 +673,7 @@ - SIGUSR2 + SIGUSR2 When this signal is received the systemd manager will log @@ -482,7 +684,7 @@ - SIGHUP + SIGHUP Reloads the complete daemon configuration. This is mostly @@ -491,7 +693,7 @@ - SIGRTMIN+0 + SIGRTMIN+0 Enters default mode, starts the default.target @@ -501,7 +703,7 @@ - SIGRTMIN+1 + SIGRTMIN+1 Enters rescue mode, starts the @@ -512,7 +714,7 @@ - SIGRTMIN+2 + SIGRTMIN+2 Enters emergency mode, starts the @@ -523,7 +725,7 @@ - SIGRTMIN+3 + SIGRTMIN+3 Halts the machine, starts the @@ -534,7 +736,7 @@ - SIGRTMIN+4 + SIGRTMIN+4 Powers off the machine, starts the @@ -545,7 +747,7 @@ - SIGRTMIN+5 + SIGRTMIN+5 Reboots the machine, starts the @@ -554,13 +756,116 @@ systemctl start reboot.target. + + + SIGRTMIN+6 + + Reboots the machine via kexec, + starts the + kexec.target + unit. This is mostly equivalent to + systemctl start + kexec.target. + + + + SIGRTMIN+13 + + Immediately halts the machine. + + + + SIGRTMIN+14 + + Immediately powers off the machine. + + + + SIGRTMIN+15 + + Immediately reboots the machine. + + + + SIGRTMIN+16 + + Immediately reboots the machine with kexec. + + + + SIGRTMIN+20 + + Enables display of + status messages on the console, as + controlled via + systemd.show_status=1 + on the kernel command + line. + + + + SIGRTMIN+21 + + Disables display of + status messages on the console, as + controlled via + systemd.show_status=0 + on the kernel command + line. + + + + SIGRTMIN+22 + SIGRTMIN+23 + + Sets the log level to + debug + (or info on + SIGRTMIN+23), as + controlled via + systemd.log_level=debug + (or systemd.log_level=info + on SIGRTMIN+23) on + the kernel command + line. + + + + SIGRTMIN+24 + + Immediately exits the + manager (only available for --user + instances). + + + + SIGRTMIN+26 + SIGRTMIN+27 + SIGRTMIN+28 + + Sets the log level to + journal-or-kmsg (or + console on + SIGRTMIN+27, + kmsg on + SIGRTMIN+28), as + controlled via + systemd.log_target=journal-or-kmsg + (or + systemd.log_target=console + on SIGRTMIN+27 or + systemd.log_target=kmsg + on SIGRTMIN+28) + on the kernel command + line. + Environment - + $SYSTEMD_LOG_LEVEL systemd reads the @@ -600,7 +905,7 @@ $XDG_DATA_HOME $XDG_DATA_DIRS - The systemd session + The systemd user manager uses these variables in accordance to the XDG @@ -656,47 +961,283 @@ + + Kernel Command Line + + When run as system instance systemd parses a + number of kernel command line + argumentsIf run inside a Linux + container these arguments may be passed as command + line arguments to systemd itself, next to any of the + command line options listed in the Options section + above. If run outside of Linux containers, these + arguments are parsed from + /proc/cmdline + instead.: + + + + systemd.unit= + rd.systemd.unit= + + Overrides the unit to + activate on boot. Defaults to + default.target. This + may be used to temporarily boot into a + different boot unit, for example + rescue.target or + emergency.service. See + systemd.special7 + for details about these units. The + option prefixed with + rd. is honored + only in the initial RAM disk (initrd), + while the one that is not prefixed only + in the main system. + + + + systemd.dump_core= + + Takes a boolean + argument. If , + systemd dumps core when it + crashes. Otherwise, no core dump is + created. Defaults to + . + + + + systemd.crash_shell= + + Takes a boolean + argument. If , + systemd spawns a shell when it + crashes. Otherwise, no shell is + spawned. Defaults to + , for security + reasons, as the shell is not protected + by any password + authentication. + + + + systemd.crash_chvt= + + Takes an integer + argument. If positive systemd + activates the specified virtual + terminal when it crashes. Defaults to + -1. + + + + systemd.confirm_spawn= + + Takes a boolean + argument. If , + asks for confirmation when spawning + processes. Defaults to + . + + + + systemd.show_status= + + Takes a boolean + argument or the constant + auto. If + , shows terse + service status updates on the console + during bootup. + auto behaves like + until a service + fails or there is a significant delay + in boot. Defaults to + , unless + is passed as + kernel command line option in which + case it defaults to + auto. + + + + systemd.log_target= + systemd.log_level= + systemd.log_color= + systemd.log_location= + + Controls log output, + with the same effect as the + $SYSTEMD_LOG_TARGET, $SYSTEMD_LOG_LEVEL, $SYSTEMD_LOG_COLOR, $SYSTEMD_LOG_LOCATION + environment variables described above. + + + + systemd.default_standard_output= + systemd.default_standard_error= + Controls default + standard output and error output for + services, with the same effect as the + + and + command line arguments described + above, respectively. + + + + systemd.setenv= + + Takes a string + argument in the form VARIABLE=VALUE. + May be used to set default environment + variables to add to forked child processes. + May be used more than once to set multiple + variables. + + + + quiet + + Turn off + status output at boot, much like + systemd.show_status=false + would. Note that this option is also + read by the kernel itself and disables + kernel log output. Passing this option + hence turns off the usual output from + both the system manager and the kernel. + + + + + debug + + Turn on debugging + output. This is equivalent to + systemd.log_level=debug. + Note that this option is also read by + the kernel itself and enables kernel + debug output. Passing this option + hence turns on the debug output from + both the system manager and the + kernel. + + + + emergency + -b + + Boot into emergency + mode. This is equivalent to + systemd.unit=emergency.target + and provided for compatibility reasons + and to be easier to + type. + + + + rescue + single + s + S + 1 + + Boot into rescue + mode. This is equivalent to + systemd.unit=rescue.target + and provided for compatibility reasons + and to be easier to + type. + + + + 2 + 3 + 4 + 5 + + Boot into the + specified legacy SysV runlevel. These + are equivalent to + systemd.unit=runlevel2.target, + systemd.unit=runlevel3.target, + systemd.unit=runlevel4.target, + and systemd.unit=runlevel5.target, respectively, + and provided for compatibility reasons + and to be easier to + type. + + + + locale.LANG= + locale.LANGUAGE= + locale.LC_CTYPE= + locale.LC_NUMERIC= + locale.LC_TIME= + locale.LC_COLLATE= + locale.LC_MONETARY= + locale.LC_MESSAGES= + locale.LC_PAPER= + locale.LC_NAME= + locale.LC_ADDRESS= + locale.LC_TELEPHONE= + locale.LC_MEASUREMENT= + locale.LC_IDENTIFICATION= + + Set the system locale + to use. This overrides the settings in + /etc/locale.conf. For + more information see + locale.conf5 + and + locale7. + + + + + For other kernel command line parameters + understood by components of the core OS, please refer + to + kernel-command-line7. + + Sockets and FIFOs - @/org/freedesktop/systemd1/notify + /run/systemd/notify Daemon status - notification socket. This is an AF_UNIX - datagram socket in the Linux abstract - namespace, and is used to implement - the daemon notification logic as - implemented by + notification socket. This is an + AF_UNIX datagram socket and is used to + implement the daemon notification + logic as implemented by sd_notify3. - @/org/freedesktop/systemd1/logger + /run/systemd/shutdownd Used internally by the - systemd-logger.service - unit to connect STDOUT and/or STDERR - of spawned processes to - syslog3 - or the kernel log buffer. This is an - AF_UNIX stream socket in the Linux - abstract namespace. + shutdown8 + tool to implement delayed + shutdowns. This is an AF_UNIX datagram + socket. - @/org/freedesktop/systemd1/private + /run/systemd/private Used internally as communication channel between systemctl1 and the systemd process. This is an - AF_UNIX stream socket in the Linux - abstract namespace. This interface is - private to systemd and should not be - used in external + AF_UNIX stream socket. This interface + is private to systemd and should not + be used in external projects. @@ -718,15 +1259,20 @@ See Also + The systemd Homepage, + systemd-system.conf5, + locale.conf5, systemctl1, - systemadm1, - systemd-install1, + journalctl1, systemd-notify1, daemon7, - sd-daemon7, + sd-daemon3, systemd.unit5, systemd.special5, - pkg-config1 + pkg-config1, + kernel-command-line7, + bootup7, + systemd.directives7