[root@localhost ~]# mongod --dbpath=/usr/local/mongodb/data --logpath=/usr/local/mongodb/logs --logappend --port=27017 --fork about to fork child process, waiting until server is ready for connections. forked process: 7519 ERROR: child process failed, exited with error number 100 To see additional information in this output, start without the "--fork" option.
创建data目录
cd /usr/local/mongodb/
mkdir data
再次启动即可成功
[root@localhost mongodb]# mongod --dbpath=/usr/local/mongodb/data --logpath=/usr/local/mongodb/logs --logappend --port=27017 --fork about to fork child process, waiting until server is ready for connections. forked process: 7554 child process started successfully, parent exiting
参考：
https://blog.csdn.net/sinat_30397435/article/details/50774175
https://blog.csdn.net/mangoyiy/article/details/79302711