Find the Datastore Lun

Hi Friends,

Scenario like, My Data-center having 30 more Clusters, more data stores (luns) are mapped across the clusters(multi mapped 2 or 3 cluster single lun),

and Vm are running both clusters and single cluster, we need to find that running VM's are in single cluster lun's,

finally more Clusters reached 255 luns,we  need to remove lun's to unusable Clusters. pls help  how to find that luns.

Thanks for Advance..