diff --git a/lib/cinder b/lib/cinder
index c4a49cd992..9ff74e80be 100644
--- a/lib/cinder
+++ b/lib/cinder
@@ -68,8 +68,12 @@ CINDER_SERVICE_PROTOCOL=${CINDER_SERVICE_PROTOCOL:-$SERVICE_PROTOCOL}
 CINDER_SERVICE_LISTEN_ADDRESS=${CINDER_SERVICE_LISTEN_ADDRESS:-$SERVICE_LISTEN_ADDRESS}
 
 # What type of LVM device should Cinder use for LVM backend
-# Defaults to thin. For thick provisioning change to 'default'
-CINDER_LVM_TYPE=${CINDER_LVM_TYPE:-thin}
+# Defaults to default, which is thick, the other valid choice
+# is thin, which as the name implies utilizes lvm thin provisioning.
+# Thinly provisioned LVM volumes may be more efficient when using the Cinder
+# image cache, but there are also known race failures with volume snapshots
+# and thinly provisioned LVM volumes, see bug 1642111 for details.
+CINDER_LVM_TYPE=${CINDER_LVM_TYPE:-default}
 
 # Default backends
 # The backend format is type:name where type is one of the supported backend