系统启动流程
POST-->BIOS(Boot Sequence)-->MBR(bootloader,446)-->Kernel-->initrd-->(ROOTFS)/sbin/init(/etc/inittab)
Kernel初始化的过程:
1、设备探测2、驱动初始化(可能会从initrd(initramfs)文件中装载驱动模块)3、以只读挂载根文件系统;4、装载第一个进程init(PID:1) (rw重新挂载rootfs)initrd初始化的过程
/sbin/init:(/etc/inittab) upstart: ubuntu, d-bus, event-driven # (比传统init速度快) systemd: #(并行启动多个进程)
/sbin/init(/etc/inittab) 的初始化过程
rh6采用upstart,inittab无需过多配置
[root@localhost ~]# cat /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 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:5:initdefault:[root@localhost ~]#[root@localhost ~]# uname -aLinux localhost 2.6.32-504.el6.x86_64 #1 SMP Tue Sep 16 01:56:35 EDT 2014 x86_64 x86_64 x86_64 GNU/Linux[root@localhost ~]# ls /etc/init #(inittab切割为多个*.conf文件;事件驱动)control-alt-delete.conf plymouth-shutdown.conf rc.conf rcS-sulogin.conf readahead-disable-services.conf start-ttys.confinit-system-dbus.conf prefdm.conf rcS.conf readahead-collector.conf serial.conf tty.confkexec-disable.conf quit-plymouth.conf rcS-emergency.conf readahead.conf splash-manager.conf[root@localhost ~]#[root@localhost ~]# cat /etc/init/rcS.conf #(事件驱动)# rcS - runlevel compatibility## This task runs the old sysv-rc startup scripts.## Do not edit this file directly. If you want to change the behaviour,# please create a file rcS.override and put your changes there.start on startupstop on runleveltask# Note: there can be no previous runlevel here, if we have one it's bad# information (we enter rc1 not rcS for maintenance). Run /etc/rc.d/rc# without information so that it defaults to previous=N runlevel=S.console outputpre-start script for t in $(cat /proc/cmdline); do case $t in emergency) start rcS-emergency break ;; esac doneend scriptexec /etc/rc.d/rc.sysinitpost-stop script if [ "$UPSTART_EVENTS" = "startup" ]; then [ -f /etc/inittab ] && runlevel=$(/bin/awk -F ':' '$3 == "initdefault" && $1 !~ "^#" { print $2 }' /etc/inittab) [ -z "$runlevel" ] && runlevel="3" for t in $(cat /proc/cmdline); do case $t in -s|single|S|s) runlevel="S" ;; [1-9]) runlevel="$t" ;; esac done exec telinit $runlevel fiend script[root@localhost ~]#
主要分析rh5的inittab作用
(每一行代表运行一个进程)
id:3:initdefault:id:runlevels:action:processid: 标识符runlevels: 在哪个级别运行此行;action: 在什么情况下执行此行;process: 要运行程序;si::sysinit:/etc/rc.d/rc.sysinit action:initdefault: 设定默认运行级别sysinit: 系统初始化wait: 等待级别切换至此级别时执行respawn: 一旦程序终止,会重新启动
总结inittab脚本任务
/etc/inittab的任务:
1、设定默认运行级别;2、运行系统初始化脚本;3、运行指定运行级别对应的目录下的脚本;4、设定Ctrl+Alt+Del组合键的操作;5、定义UPS电源在电源故障/恢复时执行的操作;6、启动虚拟终端(2345级别);7、启动图形终端(5级别);
学习脚本:/etc/rc.d/rc.sysinit完成的任务(系统初始化):
[root@localhost ~]# wc -l /etc/rc.d/rc.sysinit 681 /etc/rc.d/rc.sysinit[root@localhost ~]# file /etc/rc.d/rc.sysinit /etc/rc.d/rc.sysinit: Bourne-Again shell script text executable
1、激活udev和selinux; (前200行左右)
2、根据/etc/sysctl.conf文件,来设定内核参数; 3、设定时钟时钟;4、装载键盘映射;5、启用交换分区;6、设置主机名;7、根文件系统检测,并以读写方式重新挂载;8、激活RAID和LVM设备;9、启用磁盘配额;10、根据/etc/fstab,检查并挂载其它文件系统;11、清理过期的锁和PID文件;for I in /etc/rc3.d/K*; do $I stopdonefor I in /etc/rc3.d/S*; do $I startdone
##: 关闭或启动的优先次序,数据越小越优先被选定先关闭以K开头的服务,后启动以S开头的服务;
[root@localhost ~]# cat /etc/rc.d/rc#! /bin/bash## rc This file is responsible for starting/stopping# services when the runlevel changes.## Original Author: # Miquel van Smoorenburg,#set -m# check a file to be a correct runlevel scriptcheck_runlevel (){ # Check if the file exists at all. [ -x "$1" ] || return 1 is_ignored_file "$1" && return 1 return 0}# Now find out what the current and what the previous runlevel are.argv1="$1"set $(/sbin/runlevel)runlevel=$2previous=$1export runlevel previous. /etc/init.d/functionsexport CONSOLETYPEdo_confirm="no"if [ -f /var/run/confirm ]; then do_confirm="yes"fiUPSTART=[ -x /sbin/initctl ] && UPSTART=yes# See if we want to be in user confirmation modeif [ "$previous" = "N" ]; then if [ "$do_confirm" = "yes" ]; then echo $"Entering interactive startup" else echo $"Entering non-interactive startup" fifi# Get first argument. Set new runlevel to this argument.[ -n "$argv1" ] && runlevel="$argv1"# Is there an rc directory for this new runlevel?[ -d /etc/rc$runlevel.d ] || exit 0# Set language, vc settings once to avoid doing it for every init script# through functionsif [ -f /etc/sysconfig/i18n -a -z "${NOLOCALE:-}" ] ; then . /etc/profile.d/lang.sh 2>/dev/null export LANGSH_SOURCED=1fi# First, run the KILL scripts.for i in /etc/rc$runlevel.d/K* ; do # Check if the subsystem is already up. subsys=${i#/etc/rc$runlevel.d/K??} [ -f /var/lock/subsys/$subsys -o -f /var/lock/subsys/$subsys.init ] || continue check_runlevel "$i" || continue # Bring the subsystem down. [ -n "$UPSTART" ] && initctl emit --quiet stopping JOB=$subsys $i stop [ -n "$UPSTART" ] && initctl emit --quiet stopped JOB=$subsysdone# Now run the START scripts.for i in /etc/rc$runlevel.d/S* ; do # Check if the subsystem is already up. subsys=${i#/etc/rc$runlevel.d/S??} [ -f /var/lock/subsys/$subsys ] && continue [ -f /var/lock/subsys/$subsys.init ] && continue check_runlevel "$i" || continue # If we're in confirmation mode, get user confirmation if [ "$do_confirm" = "yes" ]; then confirm $subsys rc=$? if [ "$rc" = "1" ]; then continue elif [ "$rc" = "2" ]; then do_confirm="no" fi fi update_boot_stage "$subsys" # Bring the subsystem up. [ -n "$UPSTART" ] && initctl emit --quiet starting JOB=$subsys if [ "$subsys" = "halt" -o "$subsys" = "reboot" ]; then export LC_ALL=C exec $i start fi $i start [ -n "$UPSTART" ] && initctl emit --quiet started JOB=$subsysdone[ "$do_confirm" = "yes" ] && rm -f /var/run/confirmexit 0[root@localhost ~]#
启动的服务不同: 运行级别:0-6
0:halt 1: single user mode, #直接以管理员身份切入, s,S,single 2:multi user mode, no NFS 3: multi user mode, text mode 4:reserved 5: multi user mode, graphic mode 6: reboot
[root@localhost ~]# ls /etc/rc.d/rc0.d/ #(运行级别0)K01smartd K10psacct K25sshd K50snmptrapd K74ntpd K80kdump K87irqbalance K90network K99rngdK02rhsmcertd K10saslauthd K30postfix K50xinetd K75blk-availability K83bluetooth K87restorecond K92ip6tables K99sysstatK03rhnsd K15htcacheclean K30spice-vdagentd K60crond K75netfs K84NetworkManager K88auditd K92iptables S00killallK05atd K15httpd K50dnsmasq K73winbind K75ntpdate K84wpa_supplicant K88rsyslog K95firstboot S01haltK05wdaemon K16abrt-ccpp K50netconsole K74acpid K75quota_nld K85mdmonitor K89portreserve K99cpuspeedK10cups K16abrtd K50snmpd K74haldaemon K75udev-post K85messagebus K89rdisc K99lvm2-monitor[root@localhost ~]# ls /etc/rc.d/rc6.d/ #(运行级别6)K01smartd K10psacct K25sshd K50snmptrapd K74ntpd K80kdump K87irqbalance K90network K99rngdK02rhsmcertd K10saslauthd K30postfix K50xinetd K75blk-availability K83bluetooth K87restorecond K92ip6tables K99sysstatK03rhnsd K15htcacheclean K30spice-vdagentd K60crond K75netfs K84NetworkManager K88auditd K92iptables S00killallK05atd K15httpd K50dnsmasq K73winbind K75ntpdate K84wpa_supplicant K88rsyslog K95firstboot S01rebootK05wdaemon K16abrt-ccpp K50netconsole K74acpid K75quota_nld K85mdmonitor K89portreserve K99cpuspeedK10cups K16abrtd K50snmpd K74haldaemon K75udev-post K85messagebus K89rdisc K99lvm2-monitor[root@localhost ~]# ls /etc/rc.d/rc5.d/ #(运行级别5)K01smartd K50netconsole K84wpa_supplicant S08iptables S15mdmonitor S26acpid S80postfix S99firstbootK05wdaemon K50snmpd K87restorecond S10network S20kdump S26haldaemon S82abrt-ccpp S99localK10psacct K50snmptrapd K89rdisc S11auditd S22messagebus S26udev-post S82abrtdK10saslauthd K73winbind K99rngd S11portreserve S23NetworkManager S50bluetooth S90crondK15htcacheclean K74ntpd S01sysstat S12rsyslog S25blk-availability S55sshd S95atdK15httpd K75ntpdate S02lvm2-monitor S13cpuspeed S25cups S56xinetd S97rhnsdK50dnsmasq K75quota_nld S08ip6tables S13irqbalance S25netfs S70spice-vdagentd S97rhsmcertd[root@localhost ~]#
rc.d服务类脚本:
start SysV: /etc/rc.d/init.d start|stop|restart|status reload|configtest
服务类脚本遵循的规则如下(自动创建链接):
# chkconfig: runlevels SS KK 当chkconfig命令来为此脚本在rc#.d目录创建链接时,runlevels表示默认创建为S*开头的链接,-表示没有级别默认为S*开头的链接;除此之外的级别默认创建为K*开头的链接;
S后面的启动优先级为SS所表示的数字;K后面关闭优先次序为KK所表示的数字;# description: 用于说明此脚本的简单功能; \, 续行[root@localhost ~]# ls /etc/rc.d/init.d/ # (服务类脚本目录)abrt-ccpp blk-availability firstboot ip6tables lvm2-monitor NetworkManager quota_nld rsyslog snmptrapd winbindabrtd bluetooth functions iptables mdmonitor ntpd rdisc sandbox spice-vdagentd wpa_supplicantabrt-oops cpuspeed haldaemon irqbalance messagebus ntpdate restorecond saslauthd sshd xinetdacpid crond halt kdump netconsole portreserve rhnsd single sysstatatd cups htcacheclean killall netfs postfix rhsmcertd smartd udev-postauditd dnsmasq httpd lvm2-lvmetad network psacct rngd snmpd wdaemon[root@localhost ~]# cd /etc/rc.d/init.d/[root@localhost init.d]# head acpid atd==> acpid <==#!/bin/bash## /etc/rc.d/init.d/acpid## Starts the acpi daemon## chkconfig: 345 26 74 # description: Listen and dispatch ACPI events from the kernel# processname: acpid==> atd <==#!/bin/sh## atd Starts/stop the "at" daemon## chkconfig: 345 95 5# description: Runs commands scheduled by the "at" command at the time \# specified when "at" was run, and runs batch commands when the load \# average is low enough.### BEGIN INIT INFO[root@localhost init.d]#
chkconfig 编译服务类脚本为不同级别下的独立守护服务
# chkconfig: runlevels SS KK 当chkconfig命令来为此脚本在rc#.d目录创建链接时,runlevels表示默认创建为S*开头的链接,-表示没有级别默认为S*开头的链接;除此之外的级别默认创建为K*开头的链接; S后面的启动优先级为SS所表示的数字;K后面关闭优先次序为KK所表示的数字;# description: 用于说明此脚本的简单功能; \, 续行chkconfig --list: 查看所有独立守护服务的启动设定;独立守护进程! chkconfig --list SERVICE_NAME chkconfig --add SERVICE_NAMEchkconfig --del SERVICE_NAMEchkconfig [--level RUNLEVELS] SERVICE_NAME {on|off} #如果省略级别指定,默认为2345级别;
自定义服务类脚本myservice
[root@localhost init.d]# bash myservice.sh startstarting...[root@localhost init.d]# bash myservice.sh statusrunning...[root@localhost init.d]# bash myservice.sh stopstoping...[root@localhost init.d]# bash myservice.sh statusstopped[root@localhost init.d]# cat myservice.sh #!/bin/bash# chkconfig: 2345 88 11# description: my test servicelockfile=/var/lock/subsys/myservicecase $1 instart) echo "starting..." touch $lockfile ;;stop) echo "stoping..." rm -f $lockfile &> /dev/null ;;restart) echo "restarting...";;status) if [ -e $lockfile ];then echo "running..." else echo "stopped" fi ;;*) echo "`basename $0` {start|stop|restart|status}";;esac [root@localhost init.d]#
[root@localhost init.d]# chkconfig --listNetworkManager 0:off 1:off 2:on 3:on 4:on 5:on 6:offabrt-ccpp 0:off 1:off 2:off 3:on 4:off 5:on 6:offabrtd 0:off 1:off 2:off 3:on 4:off 5:on 6:offacpid 0:off 1:off 2:on 3:on 4:on 5:on 6:offatd 0:off 1:off 2:off 3:on 4:on 5:on 6:offauditd 0:off 1:off 2:on 3:on 4:on 5:on 6:offblk-availability 0:off 1:on 2:on 3:on 4:on 5:on 6:offbluetooth 0:off 1:off 2:off 3:on 4:on 5:on 6:offcpuspeed 0:off 1:on 2:on 3:on 4:on 5:on 6:offcrond 0:off 1:off 2:on 3:on 4:on 5:on 6:offcups 0:off 1:off 2:on 3:on 4:on 5:on 6:offdnsmasq 0:off 1:off 2:off 3:off 4:off 5:off 6:offfirstboot 0:off 1:off 2:off 3:on 4:off 5:on 6:offhaldaemon 0:off 1:off 2:off 3:on 4:on 5:on 6:offhtcacheclean 0:off 1:off 2:off 3:off 4:off 5:off 6:offhttpd 0:off 1:off 2:off 3:off 4:off 5:off 6:offip6tables 0:off 1:off 2:on 3:on 4:on 5:on 6:offiptables 0:off 1:off 2:on 3:on 4:on 5:on 6:offirqbalance 0:off 1:off 2:off 3:on 4:on 5:on 6:offkdump 0:off 1:off 2:off 3:on 4:on 5:on 6:offlvm2-monitor 0:off 1:on 2:on 3:on 4:on 5:on 6:offmdmonitor 0:off 1:off 2:on 3:on 4:on 5:on 6:offmessagebus 0:off 1:off 2:on 3:on 4:on 5:on 6:offnetconsole 0:off 1:off 2:off 3:off 4:off 5:off 6:offnetfs 0:off 1:off 2:off 3:on 4:on 5:on 6:offnetwork 0:off 1:off 2:on 3:on 4:on 5:on 6:offntpd 0:off 1:off 2:off 3:off 4:off 5:off 6:offntpdate 0:off 1:off 2:off 3:off 4:off 5:off 6:offportreserve 0:off 1:off 2:on 3:on 4:on 5:on 6:offpostfix 0:off 1:off 2:on 3:on 4:on 5:on 6:offpsacct 0:off 1:off 2:off 3:off 4:off 5:off 6:offquota_nld 0:off 1:off 2:off 3:off 4:off 5:off 6:offrdisc 0:off 1:off 2:off 3:off 4:off 5:off 6:offrestorecond 0:off 1:off 2:off 3:off 4:off 5:off 6:offrhnsd 0:off 1:off 2:on 3:on 4:on 5:on 6:offrhsmcertd 0:off 1:off 2:off 3:on 4:on 5:on 6:offrngd 0:off 1:off 2:off 3:off 4:off 5:off 6:offrsyslog 0:off 1:off 2:on 3:on 4:on 5:on 6:offsaslauthd 0:off 1:off 2:off 3:off 4:off 5:off 6:offsmartd 0:off 1:off 2:off 3:off 4:off 5:off 6:offsnmpd 0:off 1:off 2:off 3:off 4:off 5:off 6:offsnmptrapd 0:off 1:off 2:off 3:off 4:off 5:off 6:offspice-vdagentd 0:off 1:off 2:off 3:off 4:off 5:on 6:offsshd 0:off 1:off 2:on 3:on 4:on 5:on 6:offsysstat 0:off 1:on 2:on 3:on 4:on 5:on 6:offudev-post 0:off 1:on 2:on 3:on 4:on 5:on 6:offwdaemon 0:off 1:off 2:off 3:off 4:off 5:off 6:offwinbind 0:off 1:off 2:off 3:off 4:off 5:off 6:offwpa_supplicant 0:off 1:off 2:off 3:off 4:off 5:off 6:offxinetd 0:off 1:off 2:off 3:on 4:on 5:on 6:offxinetd based services: chargen-dgram: off chargen-stream: off daytime-dgram: off daytime-stream: off discard-dgram: off discard-stream: off echo-dgram: off echo-stream: off rsync: off tcpmux-server: off telnet: on time-dgram: off time-stream: off[root@localhost init.d]# [root@localhost init.d]# chkconfig --add myservice [root@localhost init.d]# find ./ -name myservice./myservice[root@localhost rc.d]# find ./ -name "*myservice"./init.d/myservice./rc0.d/K11myservice./rc6.d/K11myservice./rc2.d/S88myservice./rc1.d/K11myservice./rc3.d/S88myservice./rc5.d/S88myservice./rc4.d/S88myservice[root@localhost rc.d]# chkconfig --del myservice[root@localhost rc.d]# find ./ -name "*myservice"./init.d/myservice[root@localhost rc.d]# chkconfig --add myservice[root@localhost rc.d]# find ./ -name "*myservice"./init.d/myservice./rc0.d/K11myservice./rc6.d/K11myservice./rc2.d/S88myservice./rc1.d/K11myservice./rc3.d/S88myservice./rc5.d/S88myservice./rc4.d/S88myservice[root@localhost rc.d]# chkconfig --list myservicemyservice 0:off 1:off 2:on 3:on 4:on 5:on 6:off[root@localhost rc.d]# chkconfig --level 24 myservice off[root@localhost rc.d]# chkconfig --list myservicemyservice 0:off 1:off 2:off 3:on 4:off 5:on 6:off[root@localhost rc.d]#
/etc/rc.d/rc.local:系统最后启动的一个服务,准确说,应该执行的一个脚本;
[root@localhost rc.d]# cat /etc/rc.d/rc.local#!/bin/sh## This script will be executed *after* all the other init scripts.# You can put your own initialization stuff in here if you don't# want to do the full Sys V style init stuff.touch /var/lock/subsys/local[root@localhost rc.d]#
守护进程的类型:
独立守护进程 xinetd:超级守护进程,代理人 瞬时守护进程:不需要关联至运行级别[root@localhost rc.d]# chkconfig --list xinetdxinetd 0:off 1:off 2:off 3:on 4:on 5:on 6:off[root@localhost rc.d]#root@localhost rc.d]# chkconfig --list xinetdxinetd 0:off 1:off 2:off 3:on 4:on 5:on 6:off[root@localhost rc.d]# chkconfig --listNetworkManager 0:off 1:off 2:on 3:on 4:on 5:on 6:offabrt-ccpp 0:off 1:off 2:off 3:on 4:off 5:on 6:offabrtd 0:off 1:off 2:off 3:on 4:off 5:on 6:offacpid 0:off 1:off 2:on 3:on 4:on 5:on 6:offatd 0:off 1:off 2:off 3:on 4:on 5:on 6:offauditd 0:off 1:off 2:on 3:on 4:on 5:on 6:offblk-availability 0:off 1:on 2:on 3:on 4:on 5:on 6:offbluetooth 0:off 1:off 2:off 3:on 4:on 5:on 6:offcpuspeed 0:off 1:on 2:on 3:on 4:on 5:on 6:offcrond 0:off 1:off 2:on 3:on 4:on 5:on 6:offcups 0:off 1:off 2:on 3:on 4:on 5:on 6:offdnsmasq 0:off 1:off 2:off 3:off 4:off 5:off 6:offfirstboot 0:off 1:off 2:off 3:on 4:off 5:on 6:offhaldaemon 0:off 1:off 2:off 3:on 4:on 5:on 6:offhtcacheclean 0:off 1:off 2:off 3:off 4:off 5:off 6:offhttpd 0:off 1:off 2:off 3:off 4:off 5:off 6:offip6tables 0:off 1:off 2:on 3:on 4:on 5:on 6:offiptables 0:off 1:off 2:on 3:on 4:on 5:on 6:offirqbalance 0:off 1:off 2:off 3:on 4:on 5:on 6:offkdump 0:off 1:off 2:off 3:on 4:on 5:on 6:offlvm2-monitor 0:off 1:on 2:on 3:on 4:on 5:on 6:offmdmonitor 0:off 1:off 2:on 3:on 4:on 5:on 6:offmessagebus 0:off 1:off 2:on 3:on 4:on 5:on 6:offmyservice 0:off 1:off 2:off 3:on 4:off 5:on 6:offnetconsole 0:off 1:off 2:off 3:off 4:off 5:off 6:offnetfs 0:off 1:off 2:off 3:on 4:on 5:on 6:offnetwork 0:off 1:off 2:on 3:on 4:on 5:on 6:offntpd 0:off 1:off 2:off 3:off 4:off 5:off 6:offntpdate 0:off 1:off 2:off 3:off 4:off 5:off 6:offportreserve 0:off 1:off 2:on 3:on 4:on 5:on 6:offpostfix 0:off 1:off 2:on 3:on 4:on 5:on 6:offpsacct 0:off 1:off 2:off 3:off 4:off 5:off 6:offquota_nld 0:off 1:off 2:off 3:off 4:off 5:off 6:offrdisc 0:off 1:off 2:off 3:off 4:off 5:off 6:offrestorecond 0:off 1:off 2:off 3:off 4:off 5:off 6:offrhnsd 0:off 1:off 2:on 3:on 4:on 5:on 6:offrhsmcertd 0:off 1:off 2:off 3:on 4:on 5:on 6:offrngd 0:off 1:off 2:off 3:off 4:off 5:off 6:offrsyslog 0:off 1:off 2:on 3:on 4:on 5:on 6:offsaslauthd 0:off 1:off 2:off 3:off 4:off 5:off 6:offsmartd 0:off 1:off 2:off 3:off 4:off 5:off 6:offsnmpd 0:off 1:off 2:off 3:off 4:off 5:off 6:offsnmptrapd 0:off 1:off 2:off 3:off 4:off 5:off 6:offspice-vdagentd 0:off 1:off 2:off 3:off 4:off 5:on 6:offsshd 0:off 1:off 2:on 3:on 4:on 5:on 6:offsysstat 0:off 1:on 2:on 3:on 4:on 5:on 6:offudev-post 0:off 1:on 2:on 3:on 4:on 5:on 6:offwdaemon 0:off 1:off 2:off 3:off 4:off 5:off 6:offwinbind 0:off 1:off 2:off 3:off 4:off 5:off 6:offwpa_supplicant 0:off 1:off 2:off 3:off 4:off 5:off 6:offxinetd 0:off 1:off 2:off 3:on 4:on 5:on 6:offxinetd based services: #(瞬时守护进程) chargen-dgram: off chargen-stream: off daytime-dgram: off daytime-stream: off discard-dgram: off discard-stream: off echo-dgram: off echo-stream: off rsync: off tcpmux-server: off telnet: on time-dgram: off time-stream: off[root@localhost rc.d]# chkconfig rsync on[root@localhost rc.d]# chkconfig --listxinetd based services: chargen-dgram: off chargen-stream: off daytime-dgram: off daytime-stream: off discard-dgram: off discard-stream: off echo-dgram: off echo-stream: off rsync: on tcpmux-server: off telnet: on time-dgram: off time-stream: off