System V init
E701315
System V init is a traditional Unix initialization system that manages the startup and shutdown of services using runlevels and script-based configuration.
Observed surface forms (2)
Statements (58)
| Predicate | Object |
|---|---|
| instanceOf |
Unix software
ⓘ
init system ⓘ system initialization scheme ⓘ |
| advantage |
simplicity of shell script configuration
ⓘ
wide adoption and familiarity ⓘ |
| alsoKnownAs |
SysV init
NERFINISHED
ⓘ
System V-style init NERFINISHED ⓘ |
| basedOn | AT&T UNIX System V initialization design NERFINISHED ⓘ |
| configurationMechanism |
/etc/inittab
ⓘ
init scripts in /etc/init.d ⓘ symlink runlevel directories such as /etc/rc?.d ⓘ |
| implementsConcept |
runlevels
ⓘ
script-based service management ⓘ sequential service startup ⓘ |
| license | varies by implementation ⓘ |
| limitation |
lack of native dependency-based parallel startup
ⓘ
limited service supervision and monitoring ⓘ static runlevel model ⓘ |
| maintainedBy | various Unix and Linux distributions ⓘ |
| primaryExecutable | /sbin/init ⓘ |
| relatedConcept |
BSD init
NERFINISHED
ⓘ
runlevel scripts ⓘ |
| role |
controls transition between runlevels
ⓘ
first userspace process started by the kernel ⓘ manages system boot sequence ⓘ manages system shutdown sequence ⓘ |
| scriptLanguage | POSIX shell ⓘ |
| scriptLocation |
/etc/init.d
ⓘ
/etc/rc.d/init.d (on some systems) ⓘ |
| serviceControlCommand |
/etc/init.d/script-name restart
ⓘ
/etc/init.d/script-name start ⓘ /etc/init.d/script-name status ⓘ /etc/init.d/script-name stop ⓘ service ⓘ |
| shutdownOrderMechanism | script name prefixes such as KNNservice ⓘ |
| standardizedIn | System V Interface Definition (SVID) to some extent ⓘ |
| startupOrderMechanism | script name prefixes such as SNNservice ⓘ |
| supersededBy |
OpenRC (in some distributions)
ⓘ
Upstart (historically in some distributions) NERFINISHED ⓘ systemd (in many Linux distributions) NERFINISHED ⓘ |
| supportsRunlevel |
runlevel 0 (halt)
ⓘ
runlevel 1 (single-user mode) ⓘ runlevel 2 (multi-user, no network in some systems) ⓘ runlevel 3 (multi-user, full network) ⓘ runlevel 4 (unused or custom) ⓘ runlevel 5 (multi-user with graphical login on many Linux systems) ⓘ runlevel 6 (reboot) ⓘ |
| typicalImplementation | sysvinit package on Linux ⓘ |
| usedIn |
AIX
NERFINISHED
ⓘ
Devuan (as default init) ⓘ GNU/Linux distributions ⓘ HP-UX NERFINISHED ⓘ Slackware Linux NERFINISHED ⓘ Solaris (historically) NERFINISHED ⓘ UNIX System V NERFINISHED ⓘ many traditional Unix-like operating systems ⓘ older Debian releases ⓘ older Red Hat Linux releases NERFINISHED ⓘ |
Referenced by (9)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
sysvinit
this entity surface form:
sysvinit
this entity surface form:
sysvinit
this entity surface form:
SysV init