The error is thrown becauset the number of files monitored by the system has reached the limit.

Result: The command executed failed! Or a warning is shown (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! Run:

sudo sysctl -p

to check it.

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.

Root cause

Most answers above talk about raising the max number of watches. They don't talk about taking away the root cause. Typically, the root cause is just a matter of having watches that aren't used, they are completely redundant! This typically happens for files in node_modules. Moreover, this situation typically consumes a lot of memory unnecessarily and some older pcs may become slow because of it.

Webpack

The answer is in the webpack 5 docs: watchOptions: { ignored: /node_modules/ }. Simply read here: https://webpack.js.org/configuration/watch/#watchoptionsignored

The docs even mention this as a "tip":

If watching does not work for you, try out this option. This may help issues with NFS and machines in VirtualBox, WSL, Containers, or Docker. In those cases, use a polling interval and ignore large folders like /node_modules/ to keep CPU usage minimal.

VS Code

VS Code or any code editor creates lots of file watches too. By default many of them are completely redundant. Read more about it here: https://code.visualstudio.com/docs/setup/linux#_visual-studio-code-is-unable-to-watch-for-file-changes-in-this-large-workspace-error-enospc

delete react node_modules

rm -r node_modules

yarn or npm install

yarn start or npm start

if error occurs use this method again

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
  }

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
   

Remembering that this question is a duplicated: see this answer at original question

A simple way that solve my problem was:

npm cache clear 

best practice today is

npm cache verify 

npm or a process controlled by it is watching too many files. Updating max_user_watches on the build node can fix it forever. For debian put the following on terminal:

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

If you want know how Increase the amount of inotify watchers only click on link.

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!

In react.js show me same error i fix this way hope work in react native too

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

sudo sysctl -p

Now you can run npm start again.

npm start

I use ubuntu 20 server and i add in the file : /etc/sysctl.conf the below line

fs.inotify.max_user_watches=524288

Then save the file and run

sudo sysctl -p

After that all is works fine!

I solved this issue by using sudo ie

sudo yarn start

or

sudo npm start

Use sudo to solve this issue will force the number of watchers to be increased without apply any modifications in system settings. Use sudo to solve this kind of issue is never recommended, although it's a choice that have to be made by you, hope you choose wisely.

Generally we don't need to increase count of filewatchers In this case we will have more watchers

We need to remove redundant watchers what became zombie

The issue is that we have many filewatchers that are filling out our memory We just need remove these filewatchers (in case of node)

killall node

Easy Solution:

I found, that a previous solution worked well in my case. I removed node_modules and cleared the yarn / npm cache.

Long Tail Solution: If you want to have a long-tail solution - e.g. if you are often caught by this error - you can increase the value of allowed watchers (depending on your available memory)

To figure out the currently used amount of watchers, instead of only guessing, you can use this handy bash-script:

https://github.com/fatso83/dotfiles/blob/master/utils/scripts/inotify-consumers

I suggest to set the max_user_watches temporary to a high value:

sudo sysctl fs.inotify.max_user_watches=95524288  /run the script.

How to calculate how much you can use

Each watcher needs

• 540 bytes (32-bit system), or
• 1 kB (double - on 64-bit OS

So if you want to allow the use of 512MB (on 64Bit), you set something 524288 as a value.

The other way around, you can take the amount of memory you will set, and multiply it by 1024.

Example:

  512 * 1024 =   52488
 1024 * 1024 = 1048576 

It shows you the exact amount of the currently used inotify-consumers. So you might have a better idea, of how much you should increase the limit.

Using the sysctl -p approach after setting fs.inotify.max_user_watches did not work for me (by the way this setting was already set to a high value, likely from me trying to fix this issue a while back ago, using the commonly recommended workaround(s) above).

The best solution to the problem I found here, and below I share the performed steps in solving it - in my case the issue was spotted while running visual studio code, but solving the issue should be the same in other instances, like yours:

1. Use this script to identify which processes are requiring the most file watchers in your session.
2. You can then query the current max_user_watches value with sysctl fs.inotify.{max_queued_events,max_user_instances,max_user_watches} and then set it to a different value (a lower value may do it) sudo sysctl -w fs.inotify.max_user_watches=16384
3. Or you can simply kill the process you found in (1) that consumes the most file watchers (in my case, baloo_file)
4. The above, however, will likely need to be done again when restarting the system - the process we identified as responsible for taking much of the file watchers will (in my case - baloo_file) - will again so the same in the next boot. So to permanently fix the issue - either disable or remove this service/package. I disabled it: balooctl disable.

Now run sudo code --user-data-dir and it should open vscode with admin privileges this time. (by the way when it does not - run sudo code --user-data-dir --verbose to see what the problem is - that's how I figured out it had to do with file watchers limit).

Update:
You may configure VS code file watcher exclusion patterns as described here. This may prove to be the ultimate solution, I am just not sure you will always know beforehand which files you are NOT interested watching.

Another simple and good solution is just to add this to jest configuration:

watchPathIgnorePatterns: ["<rootDir>/node_modules/", "<rootDir>/.git/"]

This ignores the specified directories to reduce the files being scanned

if you working with vs code editor any editor that error due to large number of files in projects. node_modules and build not required in it so remove in list. that all open in vs code files menu

You have to filter unnecessary folders file sidebar

1. Goes to Code > Preferences > settings

2. in search setting search keyword "files:exclude"

3. Add pettern

**/node_modules

**/build

Now reopen the editor and that's it

While almost everyone suggests to increase a number of watchers, I couldn't agree that it is a solution. In my case I wanted to disable watcher completely, because of the tests running on CI using vui-cli plugin which starts web-pack-dev server for each test.

The problem was: when a few builds are running simultaneously they would fail because watchers limit is reached.

First things first I've tried to add the following to the vue.config.js:

module.exports = {
  devServer: {
    hot: false,
    liveReload: false
  }
}

Ref.: https://github.com/vuejs/vue-cli/issues/4368#issuecomment-515532738

And it worked locally but not on CI (apparently it stopped working locally the next day as well for some ambiguous reason).

After investigating web-pack-dev server documentation I found this: https://webpack.js.org/configuration/watch/#watch

And then this: https://github.com/vuejs/vue-cli/issues/2725#issuecomment-646777425

Long story short this what eventually solved the problem:

vue.config.js

module.exports = {
publicPath: process.env.PUBLIC_PATH,
devServer: {
    watchOptions: {
        ignored: process.env.CI ? "./": null,
  },
}

}

Vue version 2.6.14

Solution:

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

Run This Code In the Project Terminal After Running,

npm start

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).

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.

In my case in Angular 13, I added in tsconfig.spec.json

 "exclude": [
    "node_modules/",
    ".git/"
  ]

thanks @Antimatter it gaves me the trick.

2 fixes if you've already added: fs.inotify.max_user_watches=524288

1. Reboot the machine, things will work again
2. Rename the folder that is causing the issue (for me node_modules) to an arbitrary name (node_modilesa) and then rename right back. This will remove the watches that linux had put on those folders. Allowing you code as normal again.

I had many vscode projects (windows) opened. And each project window creates multiple file watchers

So closing some projects solved the issue for me.

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.

Try this , I was facing it for very long time but at the end it is solved by this,

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

The most important step after that is restart your system.

In my case, the error occured when using VSCode to open a react project with heavy dependencies. I used create-react-app (CRA) for that project.

Setting fs.inotify.max_user_watches=524288 made my computer freeze. So, I tried the solution that said to add watchOptions: { ignored: /node_modules/ } in the webpack config.

Step 1: Install react-app-rewired to my project

npm install react-app-rewired --save-dev 

Step 2: Create a config-overrides.js file in the project root directory. Same level as src, package.json, and node_modules.

/* config-overrides.js */
module.exports = function override(config, env) {
  //do stuff with the webpack config...
  config.watchOptions = {
    ...config.watchOptions,
    ignored: '**/node_modules',
  };
  return config;
};

Step 3: Replace the start, build, and test commands in package.json to use react-app-rewired. No need to modify the eject script.

  "scripts": {
    "start": "react-app-rewired start",
    "build": "react-app-rewired build",
    "test": "react-app-rewired test",
    "eject": "react-scripts eject"
    ...

Step 4:

npm start

Hope this helps those who have same limitations as me.
Steps taken from: How to update webpack config for a react project created using create-react-app?.

I solve this issue by this commande on terminal

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

To fix the ENOSPC: System limit for number of file watchers reached error in Linux, you need to increase the number of available file watchers. Follow these steps:

RUN THE FOLLOWING COMMANDS IN TERMINAL

1. Check the current limit:

   cat /proc/sys/fs/inotify/max_user_watches
   

2. Increase the limit (e.g., to 524288):

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

3. Verify the new limit:

   cat /proc/sys/fs/inotify/max_user_watches
   

4. Restart your development environment.

This should resolve the error and allow the app to run properly.

Everybody seems to be pointing at increasing the max watches, always to this magic number:

fs.inotify.max_user_watches=524288

What happens when you're already at that setting and still have the same error?

TL;DR

I think the simplest solution, before even starting meddling with obscure settings would be to simply run:

sudo sysctl -p

This alone will refresh the system and forget previous watched files. For me, it works every simgle time.

More details

As it seems, whenever you run something like npm run start|dev (depending on whether you're using Webpack or Vite), everything inside node_modules is put under watch. Have you seen node_modules? I have in a single project over 1000 folders inside it, and 96 different file types, clocking almost 35000 files!

There are rumours of an NPM package with pictures of the author's dog, or girlfriend, or both, or of a dog that is also the author's girlfriend... I forget now.

In a much more controlled fashion, Python virtual environments also have multiple files and a Django runserver will also watch everything under its purview.

Bottom line is, Linux loads all those file names into some sort of in-memory structure and they just stay there, even after you interrupt your npm run .... If you're one of those devs that reboots their laptop every day, you might never hit this. But if, like me, you hibernate because you have 10 workspaces and tons of stuff open (fullstack working on multiple projects), then this will happen, not if, but when.

So,if you're not running a ton of projects at the same time, try the little sudo sysctl -p and just be happy.

If you happen to be rich enough that your laptop can actually run all that in one go, then I'd recommend either segregate your projects into VMs, or just containerise them, because containers are like Vegas: "what goes in docker stays in docker."