centos7之后定义在/etc/rc.local的启动程序已经失效，需要定义成服务启动方式。
cat /etc/systemd/system/tomcat8.service
#默认服务的安装路径是 /usr/lib/systemd/system/nginx.service
[Unit]
Description=Tomcat8
After=network.target
[Service]
Type=forking
User=tomcat
Group=tomcat
Environment=CATALINA_PID=/opt/env/tomcat/tomcat8.pid
Environment=TOMCAT_JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.151-1.b12.el7_4.x86_64/jre/
Environment=CATALINA_HOME=/opt/env/tomcat/
Environment=CATALINA_BASE=/opt/env/tomcat/
Environment=CATALINA_OPTS=
"JAVA_OPTS=-Dfile.encoding=UTF-8 -Dnet.sf.ehcache.skipUpdateCheck=true -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -XX:+UseParNewGC -XX:MaxPermSize=256m -Xms1024m -Xmx1024m"
ExecStart=/opt/env/tomcat/bin/startup.sh
ExecStop=/bin/kill -15 $MAINPID
[Install]
WantedBy=multi-user.target# systemctl daemon-reload # systemctl restart tomcat8 # systemctl enable tomcat8
启动tomcat
systemctl start tomcat
例子2：创建一个简单的启动服务（以程序iperf为例）
$sudo yum install iperf3$ sudo adduser iperf -s /sbin/nologin$vi /etc/systemd/system/iperf3.service[Unit]
Description=iperf3 Service
After=network.target
[Service]
Type=simple
User=iperf
ExecStart=/usr/bin/iperf3 -s
Restart=on-abort
[Install]
WantedBy=multi-user.target#重新加载修改后的文件
$sudo systemctl daemon-reload
#启动
$sudo systemctl start iperf3
#查看状态
$sudo systemctl -l status iperf3
#关闭服务
$sudo systemctl stop iperf3
#开启自动启动服务
$sudo systemctl enable iperf3
#关闭自动启动服务
$sudo systemctl disable iperf3
