All Just to chip in here.
We have 3 DDR's (2 at remote sites and one in a main DC) and are seeing 4.4:1 compression. That's with a reasonable mix of data and no client side compression. Whilst dedupe isn't superb, but as we know it's generally lower with TSM anyway, a big advantage is DDR to DDR offsite replication for DR. Our nightly backup gets about 10:1 dedupe and is small enough to offsite without massive network connectivity. We also use NFS for TSM connectivity, which seems to work very well. Steven Steven Langdale Global Information Services EAME SAN/Storage Planning and Implementation ( Phone : +44 (0)1733 584175 ( Mob: +44 (0)7876 216782 ΓΌ Conference: +44 (0)208 609 7400 Code: 331817 + Email: steven.langd...@cat.com Nick Laflamme <dplafla...@gmail.com> Sent by: "ADSM: Dist Stor Manager" <ADSM-L@VM.MARIST.EDU> 13/01/2010 01:19 Please respond to "ADSM: Dist Stor Manager" <ADSM-L@VM.MARIST.EDU> To ADSM-L@VM.MARIST.EDU cc Subject Re: [ADSM-L] DataDomain VTL Caterpillar: Confidential Green Retain Until: 12/02/2010 On Jan 12, 2010, at 11:27 AM, Kelly Lipp wrote: > We have a customer that insisted on buying one of these for his TSM environment. Promised 20:1 dedup. He saw about five to one. He was in our Level 2 class telling the story. At the end he said he wouldn't buy it again. I made him repeat that part of the story... DataDomain's "Best Practices" guide for TSM tells customers not to let nodes compress data. I have to wonder how much compressing the data or not alters the dedup ratio. I'm not at all sure that we're going enforce a "no compression" policy for our clients.