X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.xml;h=fc4810767ad1b301591c070e2c928f32de6f7cbe;hp=d19094c38f933a234632c100569e12d2341305bc;hb=8112e84f657839a056afb411249a627956518b24;hpb=edb9aaa8b27adf89cc712000318b1e9cf40ea296 diff --git a/man/systemd.xml b/man/systemd.xml index d19094c38..fc4810767 100644 --- a/man/systemd.xml +++ b/man/systemd.xml @@ -45,7 +45,7 @@ systemd init - systemd System and Session Manager + systemd System and Service Manager @@ -60,7 +60,7 @@ 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. @@ -77,7 +77,7 @@ When run as system instance, systemd interprets the configuration file system.conf, otherwise - session.conf. See + user.conf. See systemd.conf5 for more information. @@ -136,39 +136,72 @@ - + Tell systemd to run a - system instance (resp. session + system instance (resp. user instance), even if the process ID is - not 1 (resp. is 1), i.e. system is not - (resp. is) run as init process. + not 1 (resp. is 1), i.e. systemd is + not (resp. is) run as init process. 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. + 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 + . - Dump core on crash. This switch has no effect when run as session instance. + Dump core on + crash. This switch has no effect when + run as user + instance. - Run shell on crash. This switch has no effect when run as session instance. + Run shell on + crash. This switch has no effect when + run as user + instance. - Ask for confirmation when spawning processes. This switch has no effect when run as session instance. + 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 + . + + + - Show terse service status information while booting. This switch has no effect when run as session instance. + Controls whether + output of SysV init scripts will be + directed to the console. This switch + has no effect when run as user + instance. Takes a boolean argument + which may be omitted which is + interpreted as + . @@ -217,6 +250,29 @@ it defaults to . + + + + + Sets the default + output resp. error output for all + services and sockets, i.e. controls + the default for + + resp. + (see + systemd.exec5 + for details). Takes one of + , + , + , + , + , + , + . If the + argument is omitted it defaults to + . + @@ -226,18 +282,29 @@ 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 + 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 as in the - process of being activated or deactivated, - i.e. between the two states. The following unit types - are available: + 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 (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 @@ -280,7 +347,7 @@ 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 @@ -288,9 +355,9 @@ 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 to activate other services when file system @@ -301,9 +368,38 @@ 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 is to activate on-boot services and other on-boot units by @@ -330,7 +426,7 @@ track of processes. Control group information is maintained in the kernel, and is accessible via the file system hierarchy (beneath - /cgroup/systemd/), or in tools + /sys/fs/cgroup/systemd/), or in tools such as ps1 (ps xawf -eo pid,user,cgroup,args @@ -382,6 +478,11 @@ ideas behind systemd please refer to the Original Design Document. + + Note that some but not all interfaces provided + by systemd are covered by the Interface + Stability Promise. @@ -399,28 +500,31 @@ 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 + should alter the content of these + directories only with the + enable and + disable commands of + the + systemctl1 tool. - 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 @@ -428,12 +532,15 @@ 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 @@ -490,12 +597,12 @@ 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. @@ -510,7 +617,7 @@ systemctl start ctl-alt-del.target. - systemd session managers + systemd user managers treat this signal the same way as SIGTERM. @@ -527,7 +634,7 @@ kbrequest.target. This signal is ignored by - systemd session + systemd user managers. @@ -636,6 +743,101 @@ 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 + (resp. info on + SIGRTMIN+32), as + controlled via + systemd.log_level=debug + (resp. systemd.log_level=info + on SIGRTMIN+23) on + the kernel command + line. + + + + SIGRTMIN+27 + SIGRTMIN+28 + SIGRTMIN+29 + + Sets the log level to + console + (resp. kmsg on + SIGRTMIN+28; + resp. syslog-or-kmsg + on SIGRTMIN+29), as + controlled via + systemd.log_target=console + (resp. systemd.log_target=kmsg + on SIGRTMIN+28; + resp + systemd.log_target=syslog-or-kmsg + on SIGRTMIN+29) on + the kernel command + line. + @@ -682,7 +884,7 @@ $XDG_DATA_HOME $XDG_DATA_DIRS - The systemd session + The systemd user manager uses these variables in accordance to the XDG @@ -759,18 +961,6 @@ units. - - 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.dump_core= @@ -788,8 +978,8 @@ Takes a boolean argument. If systemd spawns a shell when it - crashes. Otherwise no core dump is - created. Defaults to + crashes. Otherwise no shell is + spawned. Defaults to , for security reasons, as the shell is not protected by any password @@ -806,6 +996,16 @@ -1. + + systemd.confirm_spawn= + + Takes a boolean + argument. If + asks for confirmation when spawning + processes. Defaults to + . + + systemd.show_status= @@ -816,6 +1016,44 @@ . + + systemd.sysv_console= + + Takes a boolean + argument. If + output of SysV init scripts will be + directed to the console. Defaults to + , unless + is passed as + kernel command line option in which + case it defaults to + . + + + + 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/error output for + services, with the same effect as the + + resp. + command line arguments described + above. + + @@ -824,20 +1062,19 @@ - @/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/logger Used internally by the systemd-logger.service @@ -845,21 +1082,30 @@ of spawned processes to syslog3 or the kernel log buffer. This is an - AF_UNIX stream socket in the Linux - abstract namespace. + AF_UNIX stream + socket. + + + + /run/systemd/shutdownd + + Used internally by the + 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. @@ -883,7 +1129,6 @@ systemctl1, systemadm1, - systemd-install1, systemd-notify1, daemon7, sd-daemon7,