Whoah. Everyone has an opinion about Software Defined Storage (SDS) these days. That's awesome!
Unfortunately, we have some really funny ideas running around about what SDS really is. The only way to prevent this is to build up a standard definition and then compare alternates against this definition. When they don’t hold up, you have to call out those willing to twist the term. Here are some common SDS myths that we’ve seen running around the internet lately:
Myth 1: SDS Isn’t Real
Our favorite is that claim that SDS is not a real thing and therefore I can call any product I want SDS. This one is particularly awesome because it refutes itself instantly. If there is no such thing as SDS, why on earth would you even use this term? If it means nothing, then by definition your product or architecture is not SDS because SDS is nothing. See? Silly argument. SDS is a real thing and we see customers asking for SDS features daily. For vendors who claim that SDS isn’t real: stay on the path you’re on. More money for the rest of us.
Myth 2: SDS is the Same as Storage Virtualization
This one is more interesting. In this case, people are comparing two terms that are pretty loosely defined and claiming they are the same. Tougher to refute because both terms a bit fuzzy so comparing them is twice as hard as just talking about one. In looking deeper at this argument, we mostly see this being proposed by folks who already make Storage Virtualization technologies. This is red light number one. When someone takes a new term and applies it to something they’ve been doing for years, you should be suspicious. Yes, it’s possible that they were way ahead. Most likely, they’re just twisting the facts. Second, it appears that most people who use the term “Storage Virtualization” apply it to the notion of providing a software aggregation layer on top of existing storage back ends. While this is super interesting technology, it is certainly not new and it mixes data plane and control plane architecture. One thing we know for sure is that SDS implies a segregated control plane. This means that traditional Storage Virtualization products are not SDS. They may embrace SDS style control planes but the notion of a virtualized data plane is not required for SDS so they’re not synonymous.
Myth 3: SDS means Software Delivered Storage
This one is really fun. Basically, there are some vendors out there who have very cool software only storage products. We won’t name them to protect the innocent, but ten seconds on Google and you can find them. They are claiming that because they’re software only (no hardware as part of the bundle) that they’re SDS. That’s pretty silly. If you take a look at most of the major “legacy” storage players out there, what you will see is a software solution that’s bundled with hardware. The vast majority of SAN/NAS products out there are software running on pretty standard Intel/AMD hardware. They choose to bundle the hardware and software into a package to make it simpler do deploy/service and perhaps to gain some revenue on the hardware, but fundamentally all the value in the platform is software. By breaking this delivery model and selling just software, does that mean I have an SDS solution? Obviously not. SDS is not a business model. SDS is a Storage Management Architectural Model. If software only vendors want to create an abstracted control plane, then that’s great and they can support SDS. However, a traditional SAN can do the same thing if they choose to do so. There is nothing inherent to SDS that requires you to have a software only business model.
Myth 4: SDS means Object Storage
Ummm. What? We would not include this at all but there are some folks who seem to think this. The notion that object stores are somehow related to SDS is pretty bizarre but it seems to be common. Perhaps because many more modern storage systems are starting to be object based?? We don’t really know. The reality is that object stores are not new. Things like S3 and CDMI have been around for years and some of them have SDS attributes and some don’t. Object stores are really cool, but they’re data plane constructs. They are completely orthogonal to what SDS is trying to achieve.
Myth 5: Traditional SANs Cannot Support SDS
Again, quite a silly notion. As we have discussed, SDS is all about abstracting control surfaces from data plane and data services. There is no inherent reason why you cannot do this on a traditional SAN or NAS platform. What is true is that many of these platforms were designed before the concept of SDS was formalized but it’s not true that they cannot adapt to this new management paradigm. It’s up to the SAN vendors to decide how/if they want to join the SDS world or not. Since we are highly abstracted from the underlying implementation there is no reason why we cannot support traditional architectures along with newer software only or object store based systems.
Who's got more Myths?