INIT.D(7)             The SuSE boot concept             INIT.D(7)



NAME
       INIT.D - The SuSE boot concept

SYNOPSIS
       /etc/init.d/*

       /etc/sysconfig

DESCRIPTION
       The  scripts  for  controlling  the  system  are placed in
       /etc/init.d/ (they have  been  moved  accordingly  to  the
       Linux  Standard  Base (LSB) specification).  These scripts
       are executed directly or  indirectly  by  /sbin/init,  the
       father  of  all processes. The configuration of /sbin/init
       is given by the file /etc/inittab (see inittab(5)).

       At   boot   time,   the   boot   level    master    script
       /etc/init.d/boot  is called to initialise the system (e.g.
       file system check, ...).  It also executes  some  hardware
       init  scripts  linked  into  /etc/init.d/boot.d/.  Then it
       calls /etc/init.d/boot.local,  which  executes  the  local
       commands.

       After  system  startup, /sbin/init will normally switch on
       the default run level given in /etc/inittab.  It calls the
       run  level  master  script /etc/init.d/rc to start or stop
       services provided by the other scripts under /etc/init.d/.

       To  control the services of a run level, the corresponding
       scripts   are   linked   into   run   level    directories
       /etc/init.d/rc<X>.d/, where <X>=0,1,2,3,4,5,6,S is the run
       level number.

       There are two kinds of symbolic link: start  links,  which
       are  called  when  entering  a  run level, and stop links,
       which are called when leaving a run level.  Note that each
       service  in  the  run  levels 2, 3, 4, and 5 consists of a
       start and a stop link.  Within SuSE boot concept a differ
       ential link scheme is used to be able to change a runlevel
       in comparision with the former level.

       To avoid redundant starts when changing  run  levels  only
       those  services  are  started, which have no start link in
       the previous run level.  And to avoid redundant stops when
       changing run levels, only those services are stopped which
       have no start link in the current level. To  control  this
       behaviour, the names of the scripts are added on the names
       of the start and stop links.

       To control the order of  service  starts  and  stops,  the
       start  and stop links include a number in their link name.

       The system configuration files in  /etc/sysconfig  contain
       most of the variables used to configure the installed ser
       vices.  These variables can easily be changed by  YaST  or
       by  using  an  editor.  After  using an editor, the script
       /sbin/SuSEconfig must be called to distribute the settings
       into the system.

   Some details
       The  script  /etc/init.d/lpd  starts  or  stops  the  line
       printer daemon for the printing service, according to  the
       flag used:

              /etc/init.d/lpd start
       and

              /etc/init.d/lpd stop

       To  do  this  automatically in run level 3, this script is
       linked into /etc/init.d/rc3.d/  with  these  two  symbolic
       links

              /etc/init.d/rc3.d/S20lpd -> ../lpd
       and

              /etc/init.d/rc3.d/K20lpd -> ../lpd

       The  corresponding link with the letter S is used to start
       a service. For the printing service the number between the
       letter S and the name should be greater than the number of
       the start link of the network service.  The  corresponding
       link with the letter K is used to stop a service. The num
       ber of the stop link for the printing  service  should  be
       less than that of the stop link for the network service so
       that the printer daemon is stopped  before  shutting  down
       the network service.

   Run levels and their services
       0      This level is used for halting the system. The only
              valid service for this level is  the  script  halt,
              which   is  linked  into  /etc/init.d/rc0.d/.   The
              script halt executes /etc/init.d/halt.local.   Spe
              cials  system  issues  for halt or reboot should be
              added there.

       6      This level is used for rebooting  the  system.  The
              only  valid  service  for  this level is the script
              reboot, which is  linked  into  /etc/init.d/rc6.d/.
              The  script reboot executes /etc/init.d/halt.local.
              Specials system issues for halt or reboot should be
              added there.

       S      This  mode  is  used to switch from boot phase into
              single user mode.  The last valid service for  this
              mode  is  the  script  single, which is linked into
              /etc/init.d/rcS.d/.  In this mode you have only one
              console.

       1      Accordingly to the Linux Standard Base (LSB) speci
              fication this runlevel is used to switch from  nor
              mal  runlevel  into single user mode.  This is dif
              ferent from former SuSE Linux versions!

       2      The run level 2 is without remote networking.  Note
              that  on  some other systems this is identical with
              the single user mode.  This run level can have more
              than one virtual console.

       3      The  run level 3 is with network. This run level is
              for server stations not automatically running X.

       5      The level 5 is with network and xdm(1).  You should
              have  a  configured  and perfectly running X Window
              System for this work station run level.

       4      The run level 4 is not (yet) used.

       /etc/init.d/skeleton
              This script is a model for writing your  own.   You
              can  use insserv(8) to include your own script into
              a run level.


FILES
       /etc/init.d/*
       /etc/init.d/boot
       /etc/init.d/boot.local
       /etc/init.d/halt
       /etc/init.d/halt.local
       /etc/init.d/rc
       /etc/init.d/reboot
       /etc/init.d/skeleton
       /etc/init.d/single
       /etc/init.d/boot.d/S[0-9][0-9]*
       /etc/init.d/rc0.d/{K,S}[0-9][0-9]*
       /etc/init.d/rc1.d/{K,S}[0-9][0-9]*
       /etc/init.d/rc2.d/{K,S}[0-9][0-9]*
       /etc/init.d/rc3.d/{K,S}[0-9][0-9]*
       /etc/init.d/rc4.d/{K,S}[0-9][0-9]*
       /etc/init.d/rc5.d/{K,S}[0-9][0-9]*
       /etc/init.d/rc6.d/{K,S}[0-9][0-9]*
       /etc/init.d/rcS.d/{K,S}[0-9][0-9]*
       /etc/inittab
       /etc/sysconfig

SEE ALSO
       insserv(8), init(8), inittab(5), and the SuSE Linux  hand
       book, chapter The SuSE boot concept.

COPYRIGHT
       1996-2002 SuSE Linux AG, Nuernberg, Germany.

AUTHORS
       Florian  La  Roche  <http://www.suse.de/feedback>,  Werner
       Fink      <werner@suse.de>,       Burchard       Steinbild
       <http://www.suse.de/feedback>.



Version 0.4                Nov 15, 2000                 INIT.D(7)
