报错1：
[ftdc] Unclean full-time diagnostic data capture shutdown detected, found interim file, some metrics may have been lost.
解决办法：
1、删除掉diagnostic数据：
rm -f /var/lib/mongo/diagnostic.data/*2、启动mongodb。
进入MongoDB的bin目录下，
sudo ./mongod报错2：
2018-07-20T22:42:08.645+0800 I STORAGE [initandlisten] exception in initAndListen: DBPathInUse: Unable to lock the lock file:
(Unknown error). Another mongod instance is already running on the /data/db directory, terminating.
2018-07-20T22:42:08.645+0800 I CONTROL [initandlisten] now exiting
2018-07-20T22:42:08.645+0800 I CONTROL [initandlisten] shutting down with code:100
解决办法：mongodb非正常关闭 删除mongod.lock文件即可.(lock文件所在路径各有不同)
sudo rm /data/db/mongod.lock报错3：
2018-07-20T22:29:17.982+0800 I CONTROL [initandlisten] MongoDB starting : pid=3499 port=27017 dbpath=/data/db 64-bit host=xumovm
......
2018-07-20T21:12:05.974+0800 E STORAGE [initandlisten] Failed to set up listener: SocketException: Address already in use
解决办法：
找到mongo之前运行的PID号，关掉它，重新输入启动命令
sudo netstat -anp|more
激活Internet连接 (服务器和已建立连接的)
Proto Recv-Q Send-Q Local Address Foreign Address State
PID/Program name
tcp 0 0 127.0.0.1:27017 0.0.0.0:* LISTEN
2515/./mongod
sudo kill 2515
正确的关闭方法：停止Mongodb
方法一：查看进程，使用kill命令；不能使用kill -9
方法二：在在客户端进去，使用shutdown命令
/usr/local/mongodb/bin:$ ./mongod
> use admin;
switched to db admin
> db.shutdownServer();
server should be down...2018-07-20T23:06:30.230+0800 I NETWORK [initandlisten] waiting for connections on port 27017
2018-07-20T23:13:37.028+0800 I NETWORK [listener] connection accepted from 127.0.0.1:56738 #1 (1 connection now open)
2018-07-20T23:13:37.029+0800 I NETWORK [conn1] received client metadata from 127.0.0.1:56738 conn1: { application: { name: "MongoDB Shell" }, driver: { name: "MongoDB Internal Client", version: "4.0.0" }, os: { type: "Linux", name: "Ubuntu", architecture: "x86_64", version: "18.04" } }
2018-07-20T23:13:59.951+0800 I COMMAND [conn1] terminating, shutdown command received { shutdown: 1.0, $db: "admin" }
2018-07-20T23:13:59.951+0800 I NETWORK [conn1] shutdown: going to close listening sockets...
2018-07-20T23:13:59.951+0800 I NETWORK [conn1] removing socket file: /tmp/mongodb-27017.sock
2018-07-20T23:13:59.952+0800 I FTDC [conn1] Shutting down full-time diagnostic data capture
2018-07-20T23:13:59.956+0800 I STORAGE [conn1] WiredTigerKVEngine shutting down
2018-07-20T23:14:00.049+0800 I STORAGE [conn1] shutdown: removing fs lock...
2018-07-20T23:14:00.049+0800 I CONTROL [conn1] now exiting
2018-07-20T23:14:00.049+0800 I CONTROL [conn1] shutting down with code:0