我是 Rails 开发人员的新手，我已经在我的服务器上部署了 rails 应用程序。但是现在它没有启动并且在浏览器上给出错误如下：
错误信息：
There was an error while trying to write to Gemfile.lock. It is likely that you need to allow write permissions for the file at path: /var/www/PCMI/zil/Gemfile.lock (Bundler::InstallError)
异常类：
PhusionPassenger::UnknownError
应用程序根：
/var/www/PCMI/zil
回溯：
0 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/bundler-1.2.0/lib/ bundler/definition.rb 238 in `rescue in lock'
1 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/bundler-1.2.0/lib/bundler/definition.rb 223 in `lock'
2 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/bundler-1.2.0/lib/bundler/environment.rb 39 in `lock'
3 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/bundler-1.2.0/lib/bundler/runtime.rb 39 in `setup'
4 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/bundler-1.2.0/lib/bundler.rb 116 in `setup'
5 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/utils.rb 326 in `prepare_app_process'
6 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/rack/application_spawner.rb 156 in `block in initialize_server'
7 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/utils.rb 563 in `report_app_init_status'
8 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/rack/application_spawner.rb 154 in `initialize_server'
9 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server.rb 204 in `start_synchronously'
10 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server.rb 180 in `start'
11 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/rack/application_spawner.rb 129 in `start'
12 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/spawn_manager.rb 253 in `block (2 levels) in spawn_rack_application'
13 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server_collection.rb 132 in `lookup_or_add'
14 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/spawn_manager.rb 246 in `block in spawn_rack_application'
15 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server_collection.rb 82 in `block in synchronize'
16 < td=""> <> prelude> 10:in `synchronize'
17 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server_collection.rb 79 in `synchronize'
18 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/spawn_manager.rb 244 in `spawn_rack_application'
19 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/spawn_manager.rb 137 in `spawn_application'
20 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/spawn_manager.rb 275 in `handle_spawn_application'
21 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server.rb 357 in `server_main_loop'
22 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server.rb 206 in `start_synchronously'
23 /usr/local/rvm/gems/ruby-1.9.3-p125@domain_name/gems/passenger-3.0.17/helper-scripts/passenger-spawn-server 99 in `'
请检查浏览器中显示的错误。请帮助我解决我的问题。谢谢。