detect vserver before vbox, allowing "vbox-guest" status to overwrite
"vserver-host" detection
https://tickets.opscode.com/browse/OHAI-479

Eventually to be dropped in favour of using node[:virtualization][:systems]
https://tickets.opscode.com/browse/OHAI-182

--- ruby-ohai-7.4.0/lib/ohai/plugins/linux/virtualization.rb~	2014-09-06 07:18:08.000000000 +0300
+++ ruby-ohai-7.4.0/lib/ohai/plugins/linux/virtualization.rb	2014-09-18 00:30:42.946587051 +0300
@@ -101,6 +101,23 @@
       virtualization[:systems][:openvz] = "guest"
     end
 
+    # Detect Linux-VServer
+    if File.exists?("/proc/self/status")
+      proc_self_status = File.read("/proc/self/status")
+      vxid = proc_self_status.match(/^(s_context|VxID): (\d+)$/)
+      if vxid and vxid[2]
+        virtualization[:system] = "linux-vserver"
+        if vxid[2] == "0"
+          virtualization[:role] = "host"
+          virtualization[:systems]["linux-vserver"] = "host"
+        else
+          virtualization[:role] = "guest"
+          virtualization[:systems]["linux-vserver"] = "guest"
+        end
+      end
+    end
+
+
     # http://www.dmo.ca/blog/detecting-virtualization-on-linux
     if File.exists?("/usr/sbin/dmidecode")
       so = shell_out("dmidecode")
@@ -134,22 +151,6 @@
       end
     end
 
-    # Detect Linux-VServer
-    if File.exists?("/proc/self/status")
-      proc_self_status = File.read("/proc/self/status")
-      vxid = proc_self_status.match(/^(s_context|VxID): (\d+)$/)
-      if vxid and vxid[2]
-        virtualization[:system] = "linux-vserver"
-        if vxid[2] == "0"
-          virtualization[:role] = "host"
-          virtualization[:systems]["linux-vserver"] = "host"
-        else
-          virtualization[:role] = "guest"
-          virtualization[:systems]["linux-vserver"] = "guest"
-        end
-      end
-    end
-
     # Detect LXC/Docker
     #
     # /proc/self/cgroup will look like this inside a docker container: