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