suse nfs shell 解释

下面的解释可能有些不太准确，希望大家提出意见哈;我多修改，想对我自己总结知识也有帮助,所以贴出来
#! /bin/sh
# Copyright (c) 1996 - 2001 SuSE GmbH Nuernberg, Germany. All rights reserved.
#
# Author: Florian La Roche <florian@suse.de>, 1996
#       Werner Fink <werner@suse.de>, 1996,98
#       Burchard Steinbild <bs@suse.de>, 1997
#       Thorsten Kukuk <kukuk@suse.de>, 2000,01
#
# /etc/init.d/nfsserver
#
### BEGIN INIT INFO
# Provides: nfsserver
# Required-Start: $network $remote_fs $named portmap
# Required-Stop: $network portmap
# Should-Start: ypbind svcgssd idmapd
# Should-Stop:
# Default-Start: 3 5
# Default-Stop: 0 1 2 6
# Description: Start the kernel based NFS daemon
### END INIT INFO

. /etc/sysconfig/nfs ＃执行/etc/sysconfig/nfs shell文件读取里面的变量设置


# Shell functions sourced from /etc/rc.status:
#     rc_check       check and set local and overall rc status
#     rc_status     check and set local and overall rc status
#     rc_status -v   ditto but be verbose in local rc status
#     rc_status -v -r ditto and clear the local rc status
#     rc_failed     set local and overall rc status to failed
#     rc_failed <num> set local and overall rc status to <num><num>
#     rc_reset       clear local rc status (overall remains)
#     rc_exit       exit appropriate to overall rc status
. /etc/rc.status   ＃上面是/etc/rc.status执行后的状态和变量初始化设置


# First reset status of this service
rc_reset    #首先清除本地一些主要rc.status的设置

# Return values acc. to LSB for all commands but status:
# 0 - success
# 1 - generic or unspecified error
# 2 - invalid or excess argument(s)
# 3 - unimplemented feature (e.g. "reload")
# 4 - insufficient privilege
# 5 - program is not installed
# 6 - program is not configured
# 7 - program is not running
#
# Note that starting an already running service, stopping
# or restarting a not-running service as well as the restart
# with force-reload (in case signalling is not supported) are
# considered a success.

case `uname -r` in
  0.*|1.*|2.0.*) exit 3 #判断内核是否是2.0.*以上就执行,否则就退出我的内核2.6.16.13-4-default
esac

check_for_nfsdfs() {     #设置check_for_nfsdfs()函数
  HAVE_NFSDFS="no"    ＃初始HAVE_NFSDFS为"no"
  while read dummy type ; do #循环从/proc/filesystems文件读取变量 type
    if [ "$type" = "nfsd" ] ; then   ＃判断是否等于nfsd,
        HAVE_NFSDFS="yes" ＃等于就设置HAVE_NFSDFS为yes
    fi
  done < /proc/filesystems
}

case "$1" in    #变量$1读取第一个参数，然后判断是否启动，停止，重启等
  start)
    PARAMS=3   #设置PARAMS为3
    test "$USE_KERNEL_NFSD_NUMBER" -gt 0 && PARAMS="$USE_KERNEL_NFSD_NUMBER" #测试USE_KERNEL_NFSD_NUMBER大于0 与PARAMS
                            ＃等于USE_KERNEL_NFSD_NUMBER

    echo -n "Starting kernel based NFS server" ＃显示开始NFS服务
    modprobe nfsd        #内核加载NFS模块
    check_for_nfsdfs    #调用check_for_nfsdfs函数
    if [ "$HAVE_NFSDFS" = "yes" -a ! -f /proc/fs/nfsd/exports ] ; the        #判断HAVE_NFSDFS是否为yes 与 /proc/fs/nfsd/exports不存在且是普通文件
    mount -t nfsd nfsd /proc/fs/nfsd ＃条件成立 mount /proc/fs/nfsd目录
    rc_status   ＃调用/etc/rc.status设置本地的状态
    fi
    /usr/sbin/exportfs -r ＃修改nfs文件系统/var/lib/nfs/xtab 和 /etc/exports.同步
    rc_status    ＃调用/etc/rc.status设置本地的状态
    /usr/sbin/rpc.nfsd $PARAMS ＃注册rpc.nfsd行程连接
    rc_status    ＃调用/etc/rc.status设置本地的状态
    if [ -n "$MOUNTD_PORT" ] ; then ＃测试/etc/sysconfig/nfs文件的MOUNTD_PORT变量是否不为0
    startproc /usr/sbin/rpc.mountd -p $MOUNTD_PORT #开始路径确定过程 且读取路径运行的pid
    else
    startproc /usr/sbin/rpc.mountd    #开始路径确定过程
    fi
    if [ "$NFS4_SUPPORT" = "yes" ]; then    #判断是否支持 NFSv4
    checkproc /usr/sbin/rpc.idmapd #检查/usr/sbin/rpc.idmapd完整连接的过程
    if [ $? -eq 0 ] ; then ＃判断/usr/sbin/rpc.idmapd完整连接的过程是否连接成功
      ## Let idmapd know that nfs server is starting up
      /etc/init.d/idmapd reload
    fi
    fi
    rc_status -v ＃调用/etc/rc.status设置本地的状态
    ;;
  stop)
    echo -n "Shutting down kernel based NFS server" ＃显示关闭NFS服务
    killproc -n -KILL nfsd ＃杀死nfsd相关的进程
    rc_status ＃调用/etc/rc.status设置本地的状态
    killproc   -TERM /usr/sbin/rpc.mountd ＃杀死rpc.mountd相关的进程
    rc_status
    check_for_nfsdfs    #调用check_for_nfsdfs来设置HAVE_NFSDFS
    if [ "$HAVE_NFSDFS" = "yes" -a -f /proc/fs/nfsd/exports ] ; then #判断HAVE_NFSDFS是否为yes 与 /proc/fs/nfsd/exports不存在且是普通文件
    umount /proc/fs/nfsd    ＃条件成立 umount /proc/fs/nfsd目录
    rc_status        ＃调用/etc/rc.status设置本地的状态
    fi
    rc_status -v
    ;;
  try-restart)
    ## Stop the service and if this succeeds (i.e. the
    ## service was running before), start it again.
    $0 status >/dev/null && $0 restart #启动状态删除，然后重启

    # Remember status and be quiet
    rc_status
    ;;
  restart)
    ## Stop the service and regardless of whether it was
    ## running or not, start it again.
    $0 stop
    $0 start

    # Remember status and be quiet
    rc_status
    ;;
  reload|force-reload) #重新加载利用/etc/sysconfig/nfs的状态
    echo -n "Reload kernel based NFS server"
    /usr/sbin/exportfs -r
    rc_status -v
    ;;
  status)
    echo -n "Checking for kernel based NFS server: "
    ## Check status with checkproc(8), if process is running
    ## checkproc will return with exit status 0.

    # Status has a slightly different for the status command:
    # 0 - service running
    # 1 - service dead, but /var/run/ pid file exists
    # 2 - service dead, but /var/lock/ lock file exists
    # 3 - service not running

    # NOTE: checkproc returns LSB compliant status values.
    checkproc /usr/sbin/rpc.mountd #检查/usr/sbin/rpc.idmapd完整连接的过程
    rc_status        #利用/etc/sysconfig/nfs的状态
    checkproc -n nfsd
    rc_status -v
    ;;
  *)
    echo "Usage: $0 {start|stop|status|try-restart|restart|force-reload|reload}"   #否则显示相关启动的参数
    exit 1
    ;;
esac

rc_exit
Linux联盟原创，作者：上上智 转贴请标明出处

频道声明：本频道的文章除部分特别声明禁止转载的专稿外，可以自由转载.但请务必注明出出处和原始作者 文章版权归本频道与文章作者所有.对于被频道转载文章的个人和网站,我们表示深深的谢意。 原始作者:佚名 录入时间:2007-1-2 3:40:06 信息来源:不详 投稿信箱:itqoo@126.com