Service Level LUN Scan is the underlying mechanism StorageScope uses for its Service Level/Tiering support.  Basically, when you define tiers and service levels, the LUN Scan mechanism will "tag" those LUNs with the appropriate service level.  This is needed for the new "by Service Level" queries that were added in UB7, i.e. Storage Group Storage by Service Level, Array Storage by Service Level, etc.
We recently upgraded to ECC 6.1UB7. I seen this "Service Level lun scan is currently disabled, to enable click Enable button." under the service levels section. Can someone tell what are the benefits of enabling this and if there are any caviots? 
Service Level lun scan