Well, generally speaking with any Dedup product you don't want the nodes compressing the data. As we stand now, they don't, as the Tape Drive Hardware compression is much better, and it's easier on the node's processors, anyway. And, with a VTL/DL that does both, compression and Dedup you don't have the problem of needing larger and larger Disk Storage Pools because you can send the clients straight to the VTL. The only down side is that you send "more" data over the wire.
See Ya' Howard Coles Jr. John 3:16! -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[email protected]] On Behalf Of Nick Laflamme Sent: Tuesday, January 12, 2010 7:19 PM To: [email protected] Subject: Re: [ADSM-L] DataDomain VTL 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.
