mongodb的安装：

1.MongoDB 源码下载地址：https://www.mongodb.com/download-center#community

Ubuntu下mongodb的安装与使用_环境变量

2.vim /etc/profile修改环境变量：末尾添加

export PATH=$PATH:/home/no4/mongodb/bin


3.source /etc/profile

避免每次都要使用source /etc/profile使环境变量文件生效的方法：

    sudo su
    vim ~/.bashrc

 
末尾添加source /etc/profile

4.新建配置文件mongod.conf

    systemLog:
        destination: file
        path: "/home/no4/mongodata/log/mongod.log"
        logAppend: true
    storage:
        dbPath: "/home/no4/mongodata/db"
        journal:
           enabled: true
    processManagement:
        fork: true
    net:
        bindIp: localhost
        port: 27017

 



5.在配置文件所指定的位置建立对应的文件夹

6.mongod -f /home/no4/mongodb/mongod.conf命令启动mongodb服务器，正常输出如下：

    root@no4-Default-string:/home/no4# mongod -f ./mongodb/mongod.conf
    about to fork child process, waiting until server is ready for connections.
    forked process: 11330
    child process started successfully, parent exiting

 


如果是这样：

    root@no4-Default-string:/home/no4# mongod -f ./mongodb/mongod.conf
    about to fork child process, waiting until server is ready for connections.
    forked process: 11306
    ERROR: child process failed, exited with 48
    To see additional information in this output, start without the "--fork" option.

 

一般是因为之前已经启动过了mongodb，使用ps -ef|grep mongod查找mongod相关进程，然后杀掉后再重试。

7.输入mongo连接服务器，再输入show dbs查看数据库，正常输出如下：

    > show dbs
    admin   0.000GB
    config  0.000GB
    local   0.000GB