開機流程

1. 第一支程式 init 及設定檔 /etc/inittab 與 runlevel
   

   [root@dywOffice ~]# vi /etc/inittab
   # inittab is only used by upstart for the default runlevel.
   # ADDING OTHER CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.
   # System initialization is started by /etc/init/rcS.conf
   # Individual runlevels are started by /etc/init/rc.conf
   # Ctrl-Alt-Delete is handled by /etc/init/control-alt-delete.conf
   # Terminal gettys are handled by /etc/init/tty.conf and /etc/init/serial.conf,
   # with configuration in /etc/sysconfig/init.
   # For information on how to write upstart event handlers, or how
   # upstart works, see init(5), init(8), and initctl(8).
   
   # Default runlevel. The runlevels used by Mandrakelinux are:
   #   0 - halt (Do NOT set initdefault to this)
   #   1 - Single user mode
   #   2 - Multiuser, without NFS (The same as 3, if you do not have networking)
   #   3 - Full multiuser mode
   #   4 - unused
   #   5 - X11
   #   6 - reboot (Do NOT set initdefault to this)
   #
   id:3:initdefault:
   

2. 各開機層級啟動設定
   

   [root@deyu ~]# cat /etc/init/rc.conf 
   # rc - System V runlevel compatibility
   # This task runs the old sysv-rc runlevel scripts.  It
   # is usually started by the telinit compatibility wrapper.
   
   start on runlevel [0123456]
   stop on runlevel [!$RUNLEVEL]
   task
   export RUNLEVEL
   console output
   exec /etc/rc.d/rc $RUNLEVEL
   

3. run level 3 的啟動目錄放在 /etc/rc.d/rc3.d 目錄當中：
   

   [root@deyu ~]# ll /etc/rc.d/rc3.d/
   total 0
   lrwxrwxrwx. 1 root root 20 Dec 11 14:01 K01certmonger -> ../init.d/certmonger
   lrwxrwxrwx. 1 root root 16 Dec 11 14:04 K01smartd -> ../init.d/smartd
   lrwxrwxrwx. 1 root root 17 Dec 11 14:01 K02oddjobd -> ../init.d/oddjobd
   lrwxrwxrwx. 1 root root 16 Dec 11 14:05 K10psacct -> ../init.d/psacct
   lrwxrwxrwx. 1 root root 19 Dec 11 14:01 K10saslauthd -> ../init.d/saslauthd
   ...........................
   lrwxrwxrwx. 1 root root 15 Dec 11 14:01 K86cgred -> ../init.d/cgred
   lrwxrwxrwx. 1 root root 21 Dec 11 14:01 K87restorecond -> ../init.d/restorecond
   lrwxrwxrwx. 1 root root 15 Dec 11 14:01 K89rdisc -> ../init.d/rdisc
   lrwxrwxrwx. 1 root root 23 Dec 11 14:05 S00microcode_ctl -> ../init.d/microcode_ctl
   lrwxrwxrwx. 1 root root 17 Dec 11 14:04 S01sysstat -> ../init.d/sysstat
   lrwxrwxrwx. 1 root root 22 Dec 11 14:01 S02lvm2-monitor -> ../init.d/lvm2-monitor
   lrwxrwxrwx. 1 root root 18 Dec 11 14:04 S05cgconfig -> ../init.d/cgconfig
   lrwxrwxrwx. 1 root root 16 Dec 11 14:01 S07iscsid -> ../init.d/iscsid
   .................
   lrwxrwxrwx. 1 root root 19 Dec 11 14:02 S99firstboot -> ../init.d/firstboot
   lrwxrwxrwx. 1 root root 11 Dec 11 14:01 S99local -> ../rc.local
   
   ## Snn:start nn:啟動順序
   ## Knn:stop  nn:關閉順序
   ## S99local 自訂開機執行程式可以放/etc/rc.d/rc.local，系統於開機最後啟動。
   

4. 載入終端機
   

   [root@deyu ~]# vi /etc/init/tty.conf
   # tty - getty
   # This service maintains a getty on the sepcified device.
   
   stop on runlevel [016]
   respawn
   instance $TTY
   exec /sbin/mingetty $TTY
   
   #Mandriva 2010 直接在/etc/inittab中載入
   # Run gettys in standard runlevels
   2:2345:respawn:/sbin/mingetty tty2
   3:2345:respawn:/sbin/mingetty tty3
   4:2345:respawn:/sbin/mingetty tty4
   5:2345:respawn:/sbin/mingetty tty5
   

5. 服務的相關設定檔 /etc/sysconfig：
   

   [root@deyu ~]# ls /etc/sysconfig/
   atd              grub              libvirtd         rsyslog
   auditd           httpd             libvirt-guests   samba
   authconfig       i18n              modules          sandbox
   autofs           init              named            saslauthd
   cbq              ip6tables         netconsole       selinux
   cgconfig         ip6tables-config  network          smartmontools
   cgred.conf       ip6tables.old     networking       snmpd
   clock            iptables          network-scripts  snmptrapd
   console          iptables-config   nfs              sysstat
   cpuspeed         iptables.old      nspluginwrapper  sysstat.ioconf
   crond            irqbalance        ntpd             system-config-firewall
   dhcpd            kdump             ntpdate          system-config-firewall.old
   dhcpd6           kernel            prelink          system-config-users
   dhcrelay         keyboard          raid-check       udev
   ebtables-config  ksm               readahead        wpa_supplicant
   firstboot        ldap              readonly-root    xinetd
   

   1. clock：設定 Linux 主機的時區。
   2. i18n：設定語系。
   3. network：設定主機名稱及GATEWAY 。
   4. network-scripts/：網路卡設定。