在我使用一下命令启动mongodb时，报以下错误。

mongod --dbpath /usr/local/bin/mongodb/data/db --logpath /usr/local/bin/mongodb/log  --fork

ERROR: child process failed, exited with error code 1
To see additional information in this output, start without the "--fork" option.

 原因一般是配置目录错误，我这里是log的路径配置错误，在log目录下新建空白文件“logs.log”，然后执行以下命令即可

mongod --dbpath /usr/local/bin/mongodb/data/db --logpath /usr/local/bin/mongodb/log/logs  --fork

about to fork child process, waiting until server is ready for connections.
forked process: 7930
child process started successfully, parent exiting