I am svmotion vms to a SDRS cluster but under tasks it just says applying storage DRS recommendations. how do I know what vms are being moved?
You must look at the SDRS option under rules on how each vm behaves. Each VM can have its own rule to separate or stay together for performance reasons.
From VI client,
Datastore & Datastore clusters >> Storage DRS tab (in the middle)>>History ::: From here you could know which VM is SVmotioned on which DS in datastore cluster.