When you turn on a computer that has the UNIX system installed, starting up UNIX is managed by a process called init. The init process sets many processes in motion, based on the initialization state defined in the /etc/inittab file.

This section describes what happens when you start up the UnixWare 1.1 version of the UNIX system on your personal computer, as it is delivered from Novell, Inc.

The init process starts up and checks the /etc/inittab file. The first thing init does is run processes that are marked in the inittab file as sysinit processes. sysinit processes are those that make sure the system is set up properly.

init finds the following sysinit lines in the /etc/inittab file:

cr::sysinit:/sbin/ckroot >/dev/sysmsg 2>&1

ck::sysinit:/sbin/setclk  >/dev/sysmsg 2>&1

mm::sysinit:/etc/conf/bin/idmodreg >/dev/sysmsg 2>&1

ldmd::sysinit:/etc/conf/bin/idmodload >/dev/sysmsg 2>&1

ap::sysinit:/sbin/autopush f /etc/ap/chan.ap

bchk::sysinit:/sbin/bcheckrc </dev/console >/dev/sysmsg 2>&1

bu::sysinit:/etc/conf/bin/idrebuild reboot </dev/console >/dev/sysmsg 2>&1

ia::sysinit:/sbin/creatiadb </dev/console >/dev/sysmsg 2>&1

Here's a quick rundown of what the system initialization (sysinit) processes do when you start the system:

• ckroot—This reads the mount options for the root file system from the /etc/vfstab file. These options, including the file system type, are needed to make the root file system available (that is, to mount it). ckroot also checks the file system (fsck command) if it determines that there are any problems in the file system. For example, if you turn off the system instead of doing a shutdown, the system sends you the message "Please wait while the system is examined" while it resolves any inconsistencies it finds.
  
  
• setclk—This sets the UNIX system clock from the hardware clock.
  
  
• idmodreg—This registers the loadable kernel modules listed in the /etc/mod_register file.
  
  
• idmodload—This loads the loadable kernel modules listed in the /etc/loadmods file.
  
  
• autopush—This configures a list of modules to be automatically pushed on a Streams device when the device is opened. In this case, modules listed in the /etc/ap/chan.ap file are pushed on top of the console monitor device to provide line discipline information.
  
  
• bcheckrc—This does several startup tasks, including setting your system name, mounting /proc (processes) and /dev/fd (floppy disk) devices, and checking and linking additional devices related to floppy disks.
  
  
• idrebuild—This checks whether the kernel has to be rebuilt, and if so runs the idbuild command to rebuild it. The kernel needs to be rebuilt after you add devices or change tunable parameters.
  
  
• creatiadb—This sets up security tables.
  
  

Once system initialization functions are set up, init checks the initdefault entry in the inittab to determine the run level that the system is supposed to start up in. It finds the following initdefault line:

is:3:initdefault:

This tells init to start up UNIX in run level, or system state, 3. System state 3 is defined as the remote file-sharing state. With that information stored away, init proceeds to run all commands set in the /etc/inittab file that are designated as belonging to run state 3. Here is a list:

r2:23:wait:/sbin/rc2 1> /dev/sysmsg 2>&1 </dev/console

r3:3:wait:/sbin/rc3  1> /dev/sysmsg 2>&1 </dev/console

li:23:wait:/usr/bin/ln /dev/systty /dev/syscon >/dev/null 2>&1\

     [cc]sc:234:respawn:/usr/lib/saf/sac t 300

co:12345:respawn:/usr/lib/saf/ttymon g v p "Console Login: " \

     [cc]d /dev/console l console

d2:23:wait:/sbin/dinit 1> /dev/sysmsg 2>&1 </dev/console

co:12345:once:/usr/bin/mapchan f /usr/lib/mapchan/88591.dk \

     [cc]console

The r2 and r3 lines set the most processes in action. The r2 line runs the /etc/rc2 command, which in turn starts up all scripts contained in the /etc/rc2.d directory that begin with the letter S. These include the following:

S01MOUNTFSYS S02mse      S18setuname   S50merge

S75rpc       S01tzsetclk S05RMTMPFILES S21perf

S55merge     S02PRESERVE S11uname      S27nuc

S69inet      S15mkdtab   S42els        S73snmp

You can list these files to see what they do. On the whole, however, the scripts start networking and other addon features. For example, S27nuc starts NetWare connectivity, S69inet starts TCP/IP, and S50merge starts DOS merge features.

The processes specific to state 3, file-sharing state, are started by the /etc/rc3 command. This command runs all scripts in the /etc/rc3.d directory that begin with the letter S. The file-sharing state was originally created to start the remote file sharing (RFS) application. RFS has since been overshadowed by its more popular counterpart network file system (NFS). So the /etc/rc3.d directory is usually empty unless you have purchased the NFS addon software.

When the system is operational, you will see the login screen or a console login prompt:

Console Login:

To get an idea of what's happening on a running UNIX system, the following list describes some of the processes that are running. (You can list the active processes by typing ps ef from the shell.)

• init—This runs, waiting for changes to the run state that you request with the init or telinit commands.
  
  
• sac—This manages the port monitors on your system. Port monitors are processes that listen to ports for login requests or other networking requests.
  
  
• mousemgr—This handles your mouse activities.
  
  
• in.routed—This manages your TCP/IP routing tables, keeping your system uptodate with routes to other systems on the Internet.
  
  
• nfs*—The NFS software starts up a bunch of processes that run, waiting for requests relating to sharing NFS resources.
  
  
• cron—This checks spool directories for commands that were set up to run later. It then starts those commands when they are scheduled to run.
  
  
• lpNet—This handles remote printing requests between your system and other UNIX systems.
  
  
• lpsched—This manages the printing queue for print requests on your system.
  
  

If you have logged and started up the graphical interface, you will see other processes as well. For example, the X process is the X windowing system server, and Desktop Manager (dtm) manages the windows and icons on your desktop.

Booting Multiple Operating Systems (Intel)

             Total disk size is 683 cylinders (202.8 MB)

                                Cylinders            Approx

Partition  Status     Type    Start  End Length  %     MB\

    [ic:cc]=========  ====== =========== =====  === ====== ===  ======

    1             pre5.0DOS     0   101   102   15   30.3

    2      Active UNIX System  103   681   579   85   171.9

SELECT ONE OF THE FOLLOWING:

     0.   Overwrite system master boot code

     1.   Create a partition

     2.   Change Active (Boot from) partition

     3.   Delete a partition

     4.   Update (Update disk configuration and exit)

     5.   Exit (Exit without updating disk configuration)

Enter Selection:

idtag:runstate:action:process

co:12345:respawn:ttymon g v p "Console Login: " d \

     [cc]/dev/console l console

case "$1" in

'start')

     /usr/lib/mousemgr &

     ;;

'stop')

     pid='/usr/bin/ps e | /usr/bin/grep mousemgr |\

          [cc]/usr/bin/sed e 's/^  *//' e 's/ .*//''

     if [ "${pid}" != "" ]

     then

          /usr/bin/kill ${pid}

     fi

     ;;

*)

     echo "Usage: /etc/init.d/mse { start | stop }"

     ;;

esac

S02mse start

K02mse stop

init 2

# cd /

# shutdown y g60 i0