mongoDB可以启动，但是无法启动mongo shell？

运行mongod命令，可以启动mongoDB

这应该算是成功了吧？

但是运行mongo的话，终端会报出这样的错误：

MongoDB shell version: 3.2.7
connecting to: test
2017-01-31T12:56:00.745+0800 W NETWORK  [thread1] Failed to connect to 127.0.0.1:27017, reason: errno:61 Connection refused
2017-01-31T12:56:00.745+0800 E QUERY    [thread1] Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed :
connect@src/mongo/shell/mongo.js:229:14
@(connect):1:6

exception: connect failed

不知道是为什么~求教，谢谢！