CODEWITHSUNDEEP
ruby-on-railsrubyubuntu
current_user
current_user

Reputation: 1202

Listen error: unable to monitor directories for changes

I am getting the following error while running my rails app in Ubuntu server

FATAL: Listen error: unable to monitor directories for changes. Visit https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers for info on how to fix this.

I have followed the above GitHub page, but I was unable to write in max_user_watches which were set in 8192 and I want to set that to 524288. in cat /proc/sys/fs/inotify/max_user_watches the file was in only read mode.I tried to grant write permissions, but I was getting permission denied error even with root access.

Thanks in Advance!!!

Upvotes: 75

Views: 58223

Answers (8)

Burhan
Burhan

Reputation: 39

Deleting Gemfile.lock and running 'bundle' in the project directory terminal worked for me.

Upvotes: 1

user681
user681

Reputation: 248

Adding to @mayur-shah's answer,

It worked for me after closing the server and console. So, if you are running rails server/console, close that first.

Upvotes: 0

Mayur Shah
Mayur Shah

Reputation: 3449

1000 is way too small, try with 524288 as explained in the wiki page: https://github.com/guard/listen/blob/master/README.md#increasing-the-amount-of-inotify-watchers

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.

and

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

Upvotes: 144

evedovelli
evedovelli

Reputation: 2135

I had this issue during development while running rake (even with rake -h), and the solution from https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers did not work, neither did killing the running ruby processes, killing the terminal or even restarting the computer.

To avoid this error I did a new and clean clone of my project and then rake was working (maybe git clean -fdx could have worked but I did not try it).

I was running rake version 13.0.3, rails 6.1.1, ruby 2.7.2p137.

Upvotes: 0

jamesc
jamesc

Reputation: 12837

This error occurred for me as I had a number of ruby processes currently running that I was unaware of. Just need to terminate them and all is good

Upvotes: 0

Pasupathi Thangavel
Pasupathi Thangavel

Reputation: 942

Just try to execute this from your console 

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

Hope this will work for you .

References: click here

Upvotes: 32

David
David

Reputation: 442

In my case, I just need to turn off the terminal and then start it back again. It works when I try to run rails c command :)

Upvotes: 7

Ian Link
Ian Link

Reputation: 287

For others who may have this issue. I had a VM disconnect which left the previous rails server running. Running below resolved the issue without needing to up the number of watcher.

 kill -9 $(lsof -i tcp:3000 -t)

Upvotes: 7

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