RN官方脚手架初始化问题

Question

今天尝试入门RN，第一步就跪了
全局安装脚手架后，创建了APP，但是npm start的时候报错

17:11:49: Unable to start server
See https://git.io/v5vcn for more information, either install watchman or run the following snippet:
  sudo sysctl -w kern.maxfiles=5242880
  sudo sysctl -w kern.maxfilesperproc=524288
        
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! someNative@0.1.0 start: `react-native-scripts start`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the someNative@0.1.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/wuhongsu/.npm/_logs/2017-11-28T09_11_49_264Z-debug.log

官网上有解决方法链接
但是哪位大神能给我解释以下原理，谢谢

操作系统：iOS
node： v6.11.1
npm: v4.6.1