Use shutdown instead of `halt` [GH-575]

CHANGELOG.md

@@ -4,6 +4,8 @@
     to make debugging issues easier. To enable logging, set the VAGRANT_LOG
     environmental variable to the log level you wish to see. By default,
     logging is silent.
+  - Linux uses `shutdown -h` instead of `halt` to hopefully more consistently
+    power off the system. [GH-575]
 
 ## 0.8.8 (December 1, 2011)
 

lib/vagrant/systems/linux.rb

@@ -24,7 +24,7 @@ module Vagrant
       def halt
         vm.env.ui.info I18n.t("vagrant.systems.linux.attempting_halt")
         vm.ssh.execute do |ssh|
-          ssh.exec!("sudo halt")
+          ssh.exec!("sudo shutdown -h now")
         end
 
         # Wait until the VM's state is actually powered off. If this doesn't