diff -up sos-2.2/sos/plugins/cgroups.py.orig sos-2.2/sos/plugins/cgroups.py
--- sos-2.2/sos/plugins/cgroups.py.orig	2012-03-06 13:08:55.774468733 +0000
+++ sos-2.2/sos/plugins/cgroups.py	2012-03-06 13:08:58.710468796 +0000
@@ -19,6 +19,7 @@ class cgroups(sos.plugintools.PluginBase
     """
 
     def setup(self):
+        self.addCopySpec("/proc/cgroups")
         self.addCopySpec("/etc/sysconfig/cgconfig")
         self.addCopySpec("/etc/sysconfig/cgred.conf")
         self.addCopySpec("/etc/cgsnapshot_blacklist.conf")