After my last post on VSAs I received a few notes/questions around expanding upon the benefits of VSAs over traditional arrays. I felt it will be beneficial to step back and discuss the big picture benefits of the Software Defined Storage (SDS) space in general. In this post I discuss the key attributes that are making SDS so popular.
Depending on their value proposition and play, storage vendors have different SDS definitions. For the purposes of this post I will focus on SDS solutions that completely decouple storage software from the underlying hardware. Essentially these solutions abstract the control path out of a storage solution and offer this software intelligence as a consumable service.
For me, SDS solutions provide three primary benefits- Agility, Flexibility, and Reduced CapEx costs. Agility: A key driver for SDS solutions has been the agility they offer. They enable users to scale on the go and eliminate traditional storage evils such as overprovisioning and wastage from unused resources. The portability provided by software only solutions mean that data centers can adapt to changing requirements and technology obsolescence much quicker, something that traditional arrays rarely allow.
Flexibility: Flexibility within the SDS space comes in different forms. The obvious one is the opportunity to repurpose existing hardware and/or pick your choice of the underlying hardware. You are no longer locked in with a single hardware vendor. However for me personally, the most fascinating opportunity in SDS is the ability to apply software only business models to an industry that has traditionally been restricted by physical assets- think trail licenses, paying for only the features or capacity that you need, scaling on the go, bundled offerings, etc
Reduced CapEx: Building upon my previous point around innovative business models, a trend seen in the SDS space has been that around subscription licenses. Like many software only offerings in other industries, several SDS providers offer subscription based licenses for their offerings. This means that you can now ‘lease solutions’ for a lower cost for a certain time period and renew only if you like the product. From a costs perspective, this translates into much lower CapEx costs. This shift toward recognizing more OpEx costs on your balance sheet has multiple benefits- less spending up front, more accurate budgeting, flexibility in investments, reduced taxes on your net income, and in general smoother cash flows.
Additionally selling software means much higher margins and hence vendors might be more receptive to discounts and lower prices on these solutions.
So is SDS going to take over the world?
I doubt it. At least not any time soon. SDS’s biggest advantage is also its toughest challenge. The flexibility of SDS often means that your datacenter solution can now have multiple vendors. Integrating different components can be more than a minor inconvenience. This is exactly the issue that Hyper-Converged Infrastructure vendors aim to solve when they talk about storage, compute, and networking serviced by the same vendor (Note that when HCI providers talk of being software defined, it is because they use software to automate a lot of IT tasks – a very different value proposition). However in these cases you lose out on flexibility- it really comes down to what flavor of ice-cream you prefer.
Another risk is that if you do use commodity hardware with an SDS offering, you risk having no support for the underlying hardware. Will storage architects be alright with having all that hardware risk on their hands? I’m guessing not.
In summary while SDS solutions have some way to go before they can be deployed for tier 1 applications, they do afford that flexibility, agility, and cost structure advantages that explain why these software based storage solutions are becoming more of a trend everyday.