在CentOs7x64下，安装mongodb3.2.6版本，无法启动成功。

报以下错误

# systemctl status mongod.service ● mongod.service - Mongodb Loaded: loaded (/usr/lib/systemd/system/mongod.service; enabled; vendor preset: disabled) Active: failed (Result: exit-code) since 六 2016-05-21 18:39:18 CST; 27s ago Process: 3813 ExecStart=/bin/su - mongodb -c /www/server/mongodb/bin/mongod --config /www/server/mongodb/mongodb.conf (code=exited, status=1/FAILURE) Process: 3812 ExecStartPre=/bin/rm -rf /www/data/mongodb/mongod.lock (code=exited, status=0/SUCCESS) Main PID: 3510 (code=exited, status=1/FAILURE) systemd[1]: Starting Mongodb... su[3813]: (to mongodb) root on none systemd[1]: mongod.service: control process exited, code=exited status=1 systemd[1]: Failed to start Mongodb. systemd[1]: Unit mongod.service entered failed state. systemd[1]: mongod.service failed. ------------------------------- # vi /etc/systemd/system/multi-user.target.wants/mongod.service [Unit] Description=Mongodb After=network.target remote-fs.target nss-lookup.target [Service] Type=forking PIDFile=/www/server/mongodb/mongodb.pid ExecStartPre=/bin/rm -rf /www/data/mongodb/mongod.lock ExecStart=/bin/su - mongodb -c "/www/server/mongodb/bin/mongod --config /www/server/mongodb/mongodb.conf" ExecStop=/bin/kill -2 $MAINPID KillMode=process KillSignal=SIGQUIT TimeoutStopSec=5 PrivateTmp=true [Install] WantedBy=multi-user.target