development.log报错如下：[code="java"]
ActionController::RoutingError (No route matches "/say/hello" with {:method=>:get}):
/vendor/rails/actionpack/lib/action_controller/routing/recognition_optimisation.rb:67:in recognize_path'
/vendor/rails/actionpack/lib/action_controller/routing/route_set.rb:384:inrecognize'
/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:148:in handle_request'
/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:107:indispatch'
/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:104:in synchronize'
/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:104:indispatch'
/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:120:in dispatch_cgi'
/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:35:indispatch'
/vendor/rails/railties/lib/fcgi_handler.rb:103:in process_request'
/vendor/rails/railties/lib/fcgi_handler.rb:153:inwith_signal_handler'
/vendor/rails/railties/lib/fcgi_handler.rb:101:in process_request'
/vendor/rails/railties/lib/fcgi_handler.rb:78:inprocess_each_request'
/usr/local/lib/site_ruby/1.8/fcgi.rb:612:in each_cgi'
/usr/local/lib/site_ruby/1.8/fcgi.rb:609:ineach'
/usr/local/lib/site_ruby/1.8/fcgi.rb:609:in each_cgi'
/vendor/rails/railties/lib/fcgi_handler.rb:77:inprocess_each_request'
/vendor/rails/railties/lib/fcgi_handler.rb:76:in catch'
/vendor/rails/railties/lib/fcgi_handler.rb:76:inprocess_each_request'
/vendor/rails/railties/lib/fcgi_handler.rb:50:in process!'
/vendor/rails/railties/lib/fcgi_handler.rb:24:inprocess!'
/public/dispatch.fcgi:26

Rendering /home/cmaster/web/emporium/vendor/rails/actionpack/lib/action_controller/templates/rescues/layout.erb (not_found)

[/code]

看看lighttpd启动的日志error.log

运行环境如何，怎么配置的？

[quote]顺便问一下lighttpd下可以配多个web应用吗？ [/quote]
当然可以，你的ruby和rails版本呢？

就是配置多个虚拟主机就可以了。
[code="java"]
$HTTP["host"] =~ "www.domain.com$" {
server.document-root = "/var/www/domain.com/"
server.name = "www.domain.com"
}

$HTTP["host"] =~ "www.domain2.com$" {
server.document-root = "/var/www/domain2.com"
server.name = "domain2.com"

server.error-handler-404="/index.php"

}
[/code]