【解决】Error: ENOSPC: no space left on device, watch

problem found:

Start node project ReactNativewhen an error occursError: ENOSPC: no space left on device, watch

[root@iz2zeihk6kfcls5kwmqzj1z JFReactNativeProject]# npm start

> [email protected] start /app/jenkins_workspace/workspace/JFReactNativeProject
> react-native start

┌──────────────────────────────────────────────────────────────────────────────┐
│                                                                              │
│  Running Metro Bundler on port 8081.                                         │
│                                                                              │
│  Keep Metro running while developing on any JS projects. Feel free to        │
│  close this tab and run your own Metro instance if you prefer.               │
│                                                                              │
│  https://github.com/facebook/react-native                                    │
│                                                                              │
└──────────────────────────────────────────────────────────────────────────────┘

Looking for JS files in
   /app/jenkins_workspace/workspace/JFReactNativeProject

Loading dependency graph...fs.js:1413
    throw error;
    ^

Error: ENOSPC: no space left on device, watch '/app/jenkins_workspace/workspace/JFReactNativeProject/node_modules/.staging/react-native-ddd311e5/ReactAndroid/src/androidTest/java/com/facebook/react/testing/idledetection'
    at FSWatcher.start (fs.js:1407:26)
    at Object.fs.watch (fs.js:1444:11)
    at NodeWatcher.watchdir (/app/jenkins_workspace/workspace/JFReactNativeProject/node_modules/[email protected]@sane/src/node_watcher.js:159:22)
    at Walker.<anonymous> (/app/jenkins_workspace/workspace/JFReactNativeProject/node_modules/[email protected]@sane/src/common.js:109:31)
    at Walker.emit (events.js:182:13)
    at /app/jenkins_workspace/workspace/JFReactNativeProject/node_modules/[email protected]@walker/lib/walker.js:69:16
    at go$readdir$cb (/app/jenkins_workspace/workspace/JFReactNativeProject/node_modules/[email protected]@graceful-fs/graceful-fs.js:187:14)
    at FSReqWrap.oncomplete (fs.js:169:20)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] start: `react-native start`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the [email protected] 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!     /root/.npm/_logs/2019-09-25T06_57_58_754Z-debug.log

Solution:

#表示同一用户同时可以添加的watch数目（watch一般是针对目录，决定了同时同一用户可以监控的目录数量）
[root@iz2zeihk6kfcls5kwmqzj1z JFReactNativeProject]# cat /proc/sys/fs/inotify/max_user_watches
8192
[root@iz2zeihk6kfcls5kwmqzj1z JFReactNativeProject]# echo 100000 > /proc/sys/fs/inotify/max_user_watches
[root@iz2zeihk6kfcls5kwmqzj1z JFReactNativeProject]# cat /proc/sys/fs/inotify/max_user_watches
100000

Permanent methods are as follows :( recommend using this method)

vim /etc/sysctl.conf
fs.inotify.max_user_watches = 100000（后面值根据实际情况可自行调整）
添加并运行/sbin/sysctl -p即可 

Boot authentication:

Start again, normal

[root@iz2zeihk6kfcls5kwmqzj1z JFReactNativeProject]# npm start

> [email protected] start /app/jenkins_workspace/workspace/JFReactNativeProject
> react-native start

┌──────────────────────────────────────────────────────────────────────────────┐
│                                                                              │
│  Running Metro Bundler on port 8081.                                         │
│                                                                              │
│  Keep Metro running while developing on any JS projects. Feel free to        │
│  close this tab and run your own Metro instance if you prefer.               │
│                                                                              │
│  https://github.com/facebook/react-native                                    │
│                                                                              │
└──────────────────────────────────────────────────────────────────────────────┘

Looking for JS files in
   /app/jenkins_workspace/workspace/JFReactNativeProject

Loading dependency graph, done.

Knowledge points:

The default kernel parameters of inotify

• /proc/sys/fs/inotify/max_queued_eventsDefault: 16384the file allocation value is the number of calls to inotify_init inotify instance in the event of the maximum value that can be queued, beyond this worthy event is discarded, but the event will trigger IN_Q_OVERFLOW
• /proc/sys/fs/inotify/max_user_instancesDefault: 128specifies the maximum number of inotify instatnces every real user ID can be created
• /proc/sys/fs/inotify/max_user_watchesDefault: 8192Specifies the upper limit of watches each inotify instance associated

Note: max_queued_eventsthe more frequent the maximum length of the file system changes Inotify queue management, this value should be greater
if you see in the log Event Queue Overflow, indicating that max_queued_eventsthe use of parameters need to be adjusted again too small.