"Software defined storage (SDS) is a marketing theme for promoting storage technologies that is currently lacking consensus. It is a reaction to the interest in the Software-defined networking (SDN) debate in the network product market, and Nicira's high-value acquisition."It even lists many different interpretations assigned by different vendors to the words, ranging from "policy driven storage provisioning," to "separation of storage maintenance operations from more limited storage media elements." The only external links in the article go to blogs from DataCore Software and ZadaraStorage.com. I know of some of these guys and wondered whether they were just trying to re-contextualize the story that they have been telling for years now, but using terms and language that are intended to make it sound new-ish? I did some poking around and found this piece, from a press release distributed by DataCore and published by Storage Newsletter.com in toto. As suspected, DataCore is using "SDS" to re-describe a familiar story. A storage virtualization layer enables software on storage array controllers to be abstracted away into a more portable, efficient and share-able services layer that can be associated with any workload using any generic infrastructure components (well, disk or SSD) without respect to the brand name on the outside of the crate. George Teixeira is essentially arguing that the trends that everyone is talking about (virtual apps, rise of flash SSD, need to automate the management function as storage becomes bigger, the need for improvements at the service layer -- call it a "storage hypervisor") are already being addressed by his company's product, SANsymphony-V R9. Zadara Storage, a product with which I do not have direct experience yet, is telling a similar story, but they are touting a highly manageable rig (using REST APIs!!!) to automate its deployment and use. Interesting, if a bit derivative of capabilities I already get from X-IO ISE rigs. Together, I like what both Zadara and DataCore are saying. They are trying to get storage down to its commodity hardware elements so that it can be more readily scaled and managed, both at the hardware break/fix layer and at the services layer. Gotta like that. But this is only one, and probably the only legitimate, interpretation of Software-Defined Storage. I am gathering notes on other variations.