[react-native] React Native Error: ENOSPC: System limit for number of file watchers reached

I have setup a new blank react native app.

After installing few node modules I got this error.

Running application on PGN518.
internal/fs/watchers.js:173
   throw error;
   ^

Error: ENOSPC: System limit for number of file watchers reached, watch '/home/badis/Desktop/react-native/albums/node_modules/.staging'
   at FSWatcher.start (internal/fs/watchers.js:165:26)
   at Object.watch (fs.js:1253:11)
   at NodeWatcher.watchdir (/home/badis/Desktop/react-native/albums/node modules/sane/src/node watcher. js:175:20)
   at NodeWatcher.<anonymous> (/home/badis/Desktop/react-native/albums/node modules/sane/src/node watcher. js:310:16)
   at /home/badis/Desktop/react-native/albums/node modules/graceful-fs/polyfills.js:285:20
   at FSReqWrap.oncomplete (fs.js:154:5)

I know it's related to no enough space for watchman to watch for all file changes.

I want to know what's the best course of action to take here ?

Should I ignore node_modules folder by adding it to .watchmanconfig ?

You can fix it, that increasing the amount of inotify watchers.

If you are not interested in the technical details and only want to get Listen to work:

• If you are running Debian, RedHat, or another similar Linux distribution, run the following in a terminal:

  $ echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p

• If you are running ArchLinux, run the following command instead

  $ echo fs.inotify.max_user_watches=524288 | sudo tee /etc/sysctl.d/40-max-user-watches.conf && sudo sysctl --system

Then paste it in your terminal and press on enter to run it.

The Technical Details

Listen uses inotify by default on Linux to monitor directories for changes. It's not uncommon to encounter a system limit on the number of files you can monitor. For example, Ubuntu Lucid's (64bit) inotify limit is set to 8192.

You can get your current inotify file watch limit by executing:

$ cat /proc/sys/fs/inotify/max_user_watches

When this limit is not enough to monitor all files inside a directory, the limit must be increased for Listen to work properly.

You can set a new limit temporary with:

$ sudo sysctl fs.inotify.max_user_watches=524288
$ sudo sysctl -p

If you like to make your limit permanent, use:

$ echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf
$ sudo sysctl -p

You may also need to pay attention to the values of max_queued_events and max_user_instances if listen keeps on complaining.

Please refer this link[1]. Visual Studio code has mentioned a brief explanation for this error message. I also encountered the same error. Adding the below parameter in the relavant file will fix this issue.

 fs.inotify.max_user_watches=524288

[1] https://code.visualstudio.com/docs/setup/linux#_visual-studio-code-is-unable-to-watch-for-file-changes-in-this-large-workspace-error-enospc

From the official document:

"Visual Studio Code is unable to watch for file changes in this large workspace" (error ENOSPC)

When you see this notification, it indicates that the VS Code file watcher is running out of handles because the workspace is large and contains many files. The current limit can be viewed by running:

cat /proc/sys/fs/inotify/max_user_watches

The limit can be increased to its maximum by editing

/etc/sysctl.conf

and adding this line to the end of the file:

fs.inotify.max_user_watches=524288

The new value can then be loaded in by running

sudo sysctl -p

Note that Arch Linux works a little differently, See Increasing the amount of inotify watchers for details.

While 524,288 is the maximum number of files that can be watched, if you're in an environment that is particularly memory constrained, you may wish to lower the number. Each file watch takes up 540 bytes (32-bit) or ~1kB (64-bit), so assuming that all 524,288 watches are consumed, that results in an upper bound of around 256MB (32-bit) or 512MB (64-bit).

Another option

is to exclude specific workspace directories from the VS Code file watcher with the files.watcherExclude setting. The default for files.watcherExclude excludes node_modules and some folders under .git, but you can add other directories that you don't want VS Code to track.

"files.watcherExclude": {
    "**/.git/objects/**": true,
    "**/.git/subtree-cache/**": true,
    "**/node_modules/*/**": true
  }

If you have any experience with Expo (React Native), you would know that restarting the computer if always on the table. So if it's a local situation, which happened unexpectedly, and it's not production or anything, I suggest to first RESTART YOUR COMPUTER, bcos that's what solved it for me.

I encountered this issue on a linuxmint distro. It appeared to have happened when there was so many folders and subfolders/files I added to the /public folder in my app. I applied this fix and it worked well...

$ echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf

change directory into the /etc folder: cd /etc

then run this: sudo systcl -p

You may have to close your terminal and npm start again to get it to work.

If this fails i recommend installing react-scripts globally and running your application directly with that.

$ npm i -g --save react-scripts

then instead of npm start run react-scripts start to run your application.

delete react node_modules

rm -r node_modules

yarn or npm install

yarn start or npm start

if error occurs use this method again

The meaning of this error is that the number of files monitored by the system has reached the limit!!

Result: The command executed failed! Or throw a warning (such as executing a react-native start VSCode)

Solution:

Modify the number of system monitoring files

Ubuntu

sudo gedit /etc/sysctl.conf

Add a line at the bottom

fs.inotify.max_user_watches=524288

Then save and exit!

sudo sysctl -p

to check it

Then it is solved!

I solved this issue by using sudo ie

sudo yarn start

or

sudo npm start

I had the same problem by using library wifi but when i changed my network it worked perfectly.

Change your network connection

If you are running your project in Docker, you should do the echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf and all other commands in the host machine, since the container will inherit that setting automatically (and doing it directly inside it will not work).

It happened to me with a node app I was developing on a Debian based distro. First, a simple restart solved it, but it happened again on another app.

Since it's related with the number of watchers that inotify uses to monitors files and look for changes in a directory, you have to set a higher number as limit:

I was able to solve it from the answer posted here (thanks to him!)

So, I ran:

echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p

Read more about what’s happening at https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers#the-technical-details

Hope it helps!

Late answer, and there are many good answers already.

In case you want a simple script to check if the maximum file watches is big enough, and if not, increase the limit, here it is:

#!/usr/bin/env bash

let current_watches=`sysctl -n fs.inotify.max_user_watches`

if (( current_watches < 80000 ))
then
  echo "Current max_user_watches ${current_watches} is less than 80000."
else
  echo "Current max_user_watches ${current_watches} is already equal to or greater than 80000."
  exit 0
fi

if sudo sysctl -w fs.inotify.max_user_watches=80000 && sudo sysctl -p && echo fs.inotify.max_user_watches=80000 | sudo tee /etc/sysctl.d/10-user-watches.conf
then
  echo "max_user_watches changed to 80000."
else
  echo "Could not change max_user_watches."
  exit 1
fi

The script increases the limit to 80000, but feel free to set a limit that you want.

As already pointed out by @snishalaka, you can increase the number of inotify watchers.

However, I think the default number is high enough and is only reached when processes are not cleaned up properly. Hence, I simply restarted my computer as proposed on a related github issue and the error message was gone.

1. Firstly you can run every time with root privileges

   sudo npm start

2. Or you can delete node_modules folder and use npm install to install again

3. or you can get permanent solution

   echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p