In my quest of hosting my ASP.NET Core web sites on Linux, I encounter an intermittent exception:
System.IO.IOException: The configured user limit (128) on the number of inotify instances has been reached.
at System.IO.FileSystemWatcher.StartRaisingEvents()
at System.IO.FileSystemWatcher.StartRaisingEventsIfNotDisposed()
...
This exception occurs when I instantiate a FileSystemWatcher. To protect itself, the Linux kernel has a maximum number of inotify objects it can creates. You can read more about inotify in its man page. On my VPS, the limit is by default very low: only 128. You can safely increase that number to a much higher number. Each inotify instance is about 1kB, so it won't use too much memory 😃
sudo vim /etc/sysctl.conf
Then, add the configuration line:
fs.inotify.max_user_watches=50000
Finally, reload the configuration:
sudo sysctl -p
This should solve the issue.
Here's some great links about the max_user_watches flag:
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