Failed to start mongodb.service: Unit mongodb.service not found.
hadoop@hadoop:~$ sudo service mongodb start
Failed to start mongodb.service: Unit mongodb.service not found.
解决办法：百度down来的————————
1创建配置文件：
sudo nano /etc/systemd/system/mongdb.service
[Unit]
Description=High-performance, schema-free document-oriented database
After=network.target
[Service]
User=mongodb
ExecStart=/usr/bin/mongod --quiet --config /etc/mongod.conf
[Install]
WantedBy=multi-user.target
2启动服务
sudo service mongodb start