We plan to use two Data Domain 670 or 860 in our TSM environment. Currently we use 2 IBM tape library. We backup Lotus Notes data and file services (Windows), SAP (DB2) and VMWare. Approx. 1000 nodes and 200 TB of data. So far we have nothing negative about the Data Domain systems. Are there things to note special or disadvantages which have the systems? We want to use the Data Domain at TSM 6.2.