Too many open files - Failed to initialize inotify: the user limit on the total number of inotify instances has been reached

Question

How can I fix below problem? I am using compass.

   Too many open files - Failed to initialize inotify: the user limit on the total number of inotify instances has been reached.
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/rb-inotify-0.9.5/lib/rb-inotify/notifier.rb:64:in `initialize'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/adapters/linux.rb:66:in `initialize_worker'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/adapter.rb:87:in `initialize'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/adapters/linux.rb:31:in `initialize'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/adapter.rb:226:in `works?'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/adapter.rb:190:in `usable_and_works?'
org/jruby/RubyEnumerable.java:1425:in `all?'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/adapter.rb:190:in `usable_and_works?'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/adapter.rb:57:in `select_and_initialize'
org/jruby/RubyArray.java:1613:in `each'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/adapter.rb:55:in `select_and_initialize'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/listener.rb:291:in `initialize_adapter'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/listener.rb:283:in `setup'
    /home/rmack/Downloads/compass.app/lib/ruby/jruby/listen-1.3.1-patched/lib/listen/listener.rb:65:in `start!'
    /home/rmack/Downloads/compass.app/lib/ruby/compass_1.0/sass-3.4.13/lib/sass/plugin/compiler.rb:405:in `listen_to'
    /home/rmack/Downloads/compass.app/lib/ruby/compass_1.0/sass-3.4.13/lib/sass/plugin/compiler.rb:338:in `watch'
    /home/rmack/Downloads/compass.app/lib/ruby/compass_1.0/compass-1.0.3/lib/compass/sass_compiler.rb:46:in `watch!'
    /home/rmack/Downloads/compass.app/lib/ruby/compass_1.0/compass-1.0.3/lib/compass/commands/watch_project.rb:41:in `perform'
file:/home/rmack/Downloads/compass.app/compass-app.jar!/app_watcher.rb:12:in `watch!'
file:/home/rmack/Downloads/compass.app/compass-app.jar!/ui/tray.rb:447:in `watch'

Answer 1

For Linux:

Check current value of max_user_instances:

$ cat /proc/sys/fs/inotify/max_user_instances

increase that value:

$ echo 256 > /proc/sys/fs/inotify/max_user_instances

In order to make that change permanent add a line to /etc/sysctl.conf:

fs.inotify.max_user_instances = 256