故障现象：
[root@mini-71 ~]# service nginx restart
Redirecting to /bin/systemctl restart nginx.service
Failed to restart nginx.service: Unit not found.
[root@mini-71 ~]# 解决：
创建nginx服务的管理脚本，用于启动和停止服务
vi /etc/init.d/nginx插入内容（注意nginx的安装目录）：
#!/bin/sh
# nginx - this script starts and stops the nginx daemin
#
# chkconfig: - 85 15# description: Nginx is an HTTP(S) server, HTTP(S) reverse \
# proxy and IMAP/POP3 proxy server# processname: nginx
# config: /usr/local/nginx/conf/nginx.conf
# pidfile: /usr/local/nginx/logs/nginx.pid# Source function library.. /etc/rc.d/init.d/functions# Source networking configuration.. /etc/sysconfig/network# Check that networking is up.[ "$NETWORKING" = "no" ] && exit 0nginx="/usr/local/nginx/sbin/nginx"prog=$(basename $nginx)NGINX_CONF_FILE="/usr/local/nginx/conf/nginx.conf"lockfile=/var/lock/subsys/nginxstart() {[ -x $nginx ] || exit 5[ -f $NGINX_CONF_FILE ] || exit 6echo -n $"Starting $prog: "daemon $nginx -c $NGINX_CONF_FILEretval=$?echo[ $retval -eq 0 ] && touch $lockfilereturn $retval}stop() {echo -n $"Stopping $prog: "killproc $prog -QUITretval=$?echo[ $retval -eq 0 ] && rm -f $lockfilereturn $retval}restart() {configtest || return $?stopstart}reload() {configtest || return $?echo -n $"Reloading $prog: "killproc $nginx -HUPRETVAL=$?echo}force_reload() {restart}configtest() {$nginx -t -c $NGINX_CONF_FILE}rh_status() {status $prog}rh_status_q() {rh_status >/dev/null 2>&1}case "$1" instart)rh_status_q && exit 0$1;;stop)rh_status_q || exit 0$1;;restart|configtest)$1;;reload)rh_status_q || exit 7$1;;force-reload)force_reload;;status)rh_status;;condrestart|try-restart)rh_status_q || exit 0;;*)echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload|configtest}"exit 2esac进入目录
cd /etc/init.d执行下列命令
chmod 755 /etc/init.d/nginx
chkconfig --add nginx
测试：
[root@mini-71 init.d]# service nginx restart
Restarting nginx (via systemctl): [ 确定 ]
[root@mini-71 init.d]#