I agree with JW. When it comes to Centera, a Clip is a reference point. What takes up the actual space on Centera is the 'Blobs' (individual shared parts) of the Savesets. The Clip Descriptor File (CDF) tracks what saveset references and blobs are assigned to a Clip reference. And while the EVSVR utility can request the CDF  for a Clip from Centera based on the saveset, it can only do it one at a time. EMC should be able to look directly on the Centera to get the information you need.

You can also get a list of Collected Centera Clips by running the following SQL query against the Vault Store DB:

Select RelativeFileName FROM Collection

Hope this helps.