I spent last week at a tradeshow in New York. These events are interesting because of the various end user perspectives. Those of us in the industry often get embroiled in the minutiae of products and features, and so it is very useful to understand the views of the end users on the show floor. Storage Decisions is a show that prides itself on highly qualified attendees.
One of the most curious things about the show was attendees’ obsession with inline vs post process deduplication. Numerous end users stopped by asking only about when DeltaStor deduplicates data. In the rush of the show, there was little time to discuss the question in much detail. It struck me as odd that these attendees focused on this question which in my opinion is the wrong question to ask. I can only surmise that they had gotten an earful form competing vendors who swore that inline is the best approach.
End users should not care about buzzwords like inline or post process, but rather must understand how a solution will solve their business problems. What value is inline deduplication if you can never meet your backup/restore requirements? Conversely, what value is post-process if the acquisition cost is so high that it is not cost effective? The answer in both cases is obvious. Ironically, some vendors ignore this reality and focus on only why inline is the best. The reality is that inline appliances offer limited scalability and will typically require multiple separate units to meet the needs of a large enterprise.
In order to try to bring some sanity to the question of inline vs post-process vs concurrent process, I am composing a post that will discuss the technologies in more detail. It will define the different approaches and highlight the strengths and weaknesses. Hopefully this will provide clarification. I want to emphasize that this technology choice is only a very small part of the overall deduplication solution. End users must look at deduplication solutions in the context of their environment and business challenges. Choosing a solution strictly based on when deduplication occurs can lead to major problems in the future and dramatic reductions in ROI.