I cant generate scaffold on linux platform

It use rails 3.0 v .but when I try to generate scaffold it perform me Could not find gem 'mysql2 (>= 0, runtime)' in any of the gem sources. Try running `bundle install`. I already tried but It's error and show bunch of massage Using rake (0.8.7) /usr/local/lib/site_ruby/1.8/rubygems/remote_fetcher.rb:180:in `fetch_path': SocketError: getaddrinfo: Name or service not known (http://rubygems.org/quick/Marshal.4.8/abstract-1.0.0.gemspec.rz) (Gem::RemoteFetcher::FetchError)   from /usr/local/lib/site_ruby/1.8/rubygems/spec_fetcher.rb:106:in `fetch_spec'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/remote_specification.rb:47:in `_remote_specification'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/remote_specification.rb:25:in `fetch_platform'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/source.rb:247:in `download_gem_from_uri'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/source.rb:76:in `fetch'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/installer.rb:45:in `run'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/spec_set.rb:12:in `each'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/spec_set.rb:12:in `each'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/installer.rb:44:in `run'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/installer.rb:8:in `install'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/cli.rb:217:in `install'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/vendor/thor/task.rb:22:in `send'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/vendor/thor/task.rb:22:in `run'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/vendor/thor/invocation.rb:118:in `invoke_task'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/vendor/thor.rb:246:in `dispatch'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/vendor/thor/base.rb:389:in `start'   from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/bin/bundle:13   from /usr/bin/bundle:19:in `load'   from /usr/bin/bundle:19 What ' s wrong and what should I do                                                          Very thanks again