diff --git a/xCAT-server/lib/xcat/plugins/esx.pm b/xCAT-server/lib/xcat/plugins/esx.pm
index 4d2ff634f..8a232cc84 100644
--- a/xCAT-server/lib/xcat/plugins/esx.pm
+++ b/xCAT-server/lib/xcat/plugins/esx.pm
@@ -48,6 +48,7 @@ my $vmwaresdkdetect = eval {
 
 
 my %guestidmap = (
+    "rhel.6.*" => "rhel6_",
     "rhel.5.*" => "rhel5_",
     "rhel4.*" => "rhel4_",
     "centos5.*" => "rhel5_",