Provided by: file-rc_0.8.7_all bug

NAME

       runlevel.conf - The file-rc runlevel configuration file

DESCRIPTION

       runlevel.conf  is  the  configuration  file  for the package file-rc an
       alternative  init(8)  boot  concept.   While  the  SysV   init   scheme
       implements  runlevels  through  symlinks in /etc/rc?.d/* , file-rc uses
       only one file runlevel.conf to replace all these symlinks.

       This file consists of 4 columns separated by TABs or  spaces  with  the
       following contents:

       -  The  first column is the sort criteria for starting and stopping the
          scripts.

       -  The second column consists of a comma-separated list of runlevels in
          which  the  script  should  be switched ‘off’ or a single ‘-’ if the
          script should never be stopped (within that sort-number).

       -  The third column consists of a comma-separated list of runlevels  in
          which  the  script  should  be  switched ‘on’ or a single ‘-’ if the
          script should never be started (with that sort-number).

       -  The last column specifies the full name of the script.

       Lines beginning with ‘#’ and empty lines are ignored.

   Overview
       All scripts executed by the init system are located in /etc/init.d.

       If a scripts has the .sh suffix it is a bourne shell script and MAY  be
       handled  in  an optimized manner.  The behaviour of executing script in
       an optimized way will not differ in any way from it  being  forked  and
       executed in the regular way.

       The following runlevels are defined:

       N      System bootup (NONE).

       S      Single user mode (not to be switched to directly)

       0      halt

       1      single user mode

       2..5   multi user mode

       6      reboot

   Boot
       When  the  systems  boots,  the  lines with ’S’ in the third column are
       executed.  It in turn executes all these scripts in  alphabetical  (and
       thus  numerical)  order.  The  first  argument  passed  to the executed
       scripts is start.  The runlevel at this point is ’N’ (none).

       Only things that need to be run once to get the system in a  consistent
       state  are  to be run.  The ’S’ state is NOT meant to replace rc.local.
       One should  not  start  daemons  in  this  runlevel  unless  absolutely
       necessary.  Eg,  NFS might need the portmapper, so it is OK to start it
       early in the bootprocess. But this is not the time to start  the  squid
       proxy server.

   Going multiuser
       After  the ’S’ scripts have been executed, init switches to the default
       runlevel as specified in /etc/inittab, usually ’2’.

       init(8) then executes the /etc/init.d/rc script  which  takes  care  of
       starting the services with ’2’ in the third column.

       Because the previous runlevel is ’N’ (none) the scripts with ’2’ in the
       second column will NOT be executed - there is nothing to stop yet,  the
       system is busy coming up.

       If  for  example there is a service that wants to run in runlevel 4 and
       ONLY in that level, it will place ’2,3,5’ in the second column to  stop
       the  service  when  switching out of runlevel 4.  We do not need to run
       that script at this point.

       The scripts will be executed in  alphabetical  order,  with  the  first
       argument set to ’start’.

   Switching runlevels
       When  one  switches  from  (for  example)  runlevel  2  to  runlevel 3,
       /etc/init.d/rc will first execute in  alphabetical  order  all  scripts
       with  ’3’  in  the second column with ’stop’ as first argument and then
       all scripts with  ’3’  in  the  third  column  with  ’start’  as  first
       argument.

       As an optimization, a check is made for each "service" to see if it was
       already running in the previous runlevel.  If it was, and there  is  no
       entry  present  in  the second column for the new runlevel, there is no
       need to start it a second time so that will not be done.

       On the other hand, if there was an entry in the second  column,  it  is
       assumed  the  service  was  stopped on purpose first and so needs to be
       restarted.

       We MIGHT make the same optimization for stop scripts as well  -  if  no
       entry  in the third column was present in the previous runlevel, we can
       assume that service was not running  and  we  don’t  need  to  stop  it
       either.   In  that case we can remove the "coming from level N" special
       case mentioned above.  But right now that has not been implemented.

   Single user mode
       Switching to single user mode is done by switching to runlevel 1.  That
       will  cause  all  services to be stopped (assuming they all have ’1’ in
       the second column). The runlevel 1 scripts will then switch to runlevel
       ’S’  which  has  no  scripts - all it does is spawn a shell directly on
       /dev/console for maintenance.

   Halt/reboot
       Going to runlevel 0 or  6  will  cause  the  system  to  be  halted  or
       rebooted,  respectively.   For example, if we go to runlevel 6 (reboot)
       first all scripts with ’6’  in  the  second  column  will  be  executed
       alphabetically with ’stop’ as the first argument.

       Then  the  scripts  with  ’6’  in  the  third  column  will be executed
       alphabetically with ’stop’ as the first argument as well.   The  reason
       is  that  there is nothing to start anymore at this point - all scripts
       that are run are meant to bring the system down.

EXAMPLES

       #<sort> <off>   <on>            <script>
       05      -       0               /etc/init.d/halt
       05      -       1               /etc/init.d/single
       05      -       6               /etc/init.d/reboot
       10      0,1,6   2,3,4,5         /etc/init.d/sysklogd
       12      0,1,6   2,3,4,5         /etc/init.d/kerneld
       [...]
       89      0,1,6   2,3,4,5         /etc/init.d/cron
       99      -       2,3,4,5         /etc/init.d/rmnologin
       99      0,1,6   2,3,4,5         /etc/init.d/xdm

FILES

       /etc/runlevel.conf

AUTHOR

       file-rc was originally written by Winfried  Trümper  <winni@xpilot.org>
       and  adapted  to  the Debian system by Tom Lees <tom@lpsg.demon.co.uk>,
       Martin    Schulze    <joey@debian.org>     and     Roland     Rosenfeld
       <roland@debian.org>.

       This man page was written by Roland Rosenfeld <roland@debian.org>.

SEE ALSO

       init(8)