Have any of you read “The Fabric of the Cosmos” by Brian Greene? He starts out the first chapter by describing the opening pages of a dusty old book that he read as a child where the first few lines were startling. To quote:
“There is but one truly philosophical problem…” and continues on to say “Whether the world has three dimensions or the mind nine or twelve categories, comes afterword”; such questions, the text explained, were part of the game humanity played, but they deserved attention only after the one true issue had been settled. The book was The Myth of Sisyphus written by the Algerian-born philosopher and Nobel laureate Albert Camus.
I bring this up because I believe that in the discussions around datacenter design, there is but one and only one truly important question and that is whether it makes sense to separate compute from storage. The rest of the design considerations can come later.
I would argue that binding compute to storage is inherently limiting. Why should you, the customer, be limited in your choices because the server vendor decided that they would put 16 drives in a 1U server or 24 drives in a 2U server. If the application you are running requires fewer drives, you are paying for excess electronics and capacity without ever needing it. Conversely, if your application requires more drives than can fit in a server design, you are getting short changed.
With DriveScale, all those limitations go away. We have customers who simplified their server purchasing by reducing everything to 1 SKU and are able to attach up to 40 or more hard drives to a 1U server. Drive allocation and assignment is flexible and adjustable on the fly.
And finally, one other outstanding benefit of separating storage from compute is that you, the customer, can keep storage (drives) longer; six years or more, and replace your servers more often. You can also increase the density in your server racks as these systems do not need to have any drives in them.