A free-floating buzzword
Software-defined storage is a buzzword that has received significant attention over the past few years. Despite the widespread attention the term has received, software-defined storage isn’t exactly well-defined. This is in part due to the fact that different vendors use the term for different purposes. To clarify matters, the following explores the precise meaning of software-defined storage, how it contrasts with storage virtualization, its benefits and drawbacks.
Defining terms
At a basic level, software-defined storage refers to software that decouples or abstracts storage resources form hardware. This allows storage resources to become an integrated feature of software-designed data center (SDDC) architecture where resources can be allocated automatically. According to Storage Network Industry Association (SNIA), among some of the chief characteristics of software-defined storage include automation, standard interfaces, virtualized data path, scalability and transparency.
Storage virtualization
Software-defined storage and storage virtualization are often conflated as one and the same. While the two ideas overlap, there are subtle differences between the concepts. The former involves moving the hardware layer into the software layer, which gives the server a different perspective of the physical storage than is actually the case. The latter, on the other hand, involves packaging pools of resources into containers, where a container is understood as a kind of isolated chamber that harbors all the necessary resources to run an application. The main distinction between the two is software-defined storage consists of abstracting storage services from the underlying hardware, while storage virtualization consists of detaching capacity from storage resources in order to make a pool.
Benefits
Software-defined storage has been touted for its various benefits, particular in terms of agility and cost. The technology supports both developing and transitional IT consumption models, and is intended to provide the flexibility required to respond to shifting business needs. The technology also offers metrics reporting of storage infrastructure usage. It can help make the task of provisioning storage for virtual machines easier for storage administrators as well.
Challenges
No technology is without its technical challenges. A risk of software-defined storage involves choosing the wrong vendor by failing to account for how the commodity hardware will be implemented at a particular location. New hardware doesn’t always automatically work with software-defined storage software. Although several vendors offer a hardware compatibility list for whatever software they are selling, a particular vendor’s standard for performance doesn’t always match with a specific system. Consequently, it is important for customers to test the storage software with their current storage infrastructure before making a purchase.
