Internal server error

An internal error occurred while trying to spawn the application.
Exception type: Passenger::SystemException
Error message: Cannot create a pipe: Too many open files (errno=24)
Backtrace:
     in 'void Passenger::ApplicationPool2::SmartSpawner::startPreloader()' (SmartSpawner.h:203)
     in 'virtual Passenger::ApplicationPool2::ProcessPtr Passenger::ApplicationPool2::SmartSpawner::spawn(const Passenger::ApplicationPool2::Options&)' (SmartSpawner.h:743)
     in 'void Passenger::ApplicationPool2::Group::spawnThreadRealMain(const SpawnerPtr&, const Passenger::ApplicationPool2::Options&, unsigned int)' (Implementation.cpp:956)

Error ID

Application root

/var/www/rails

Environment (value of RAILS_ENV, RACK_ENV, WSGI_ENV, NODE_ENV and PASSENGER_APP_ENV)

production

Ruby interpreter command

/home/manager/.rvm/gems/ruby-2.1.2/wrappers/ruby

User and groups

Unknown

Environment variables

Unknown

Ulimits

Unknown