Software-defined storage (SDS) is one of those terms that has been readily hijacked by vendors over the past few years. The term developed from the adoption of software-defined networking (SDN), used to define the separation of control and data traffic in the networking world, which provides the abstraction needed to deliver more efficient network management and to virtualise network functionality.
…Part of the problem with finding an adequate definition is that data storage has two components: both a persistent side for storing and recalling data, and a transmission side to cover how data passes from host to external storage. SDN by contrast only has to worry about the data transit definitions, so has fewer concerns around performance and throughput as far as an individual host is concerned. To add to the confusion, storage is moving back into the server with hyper-converged solutions, making it more difficult to come up with a consistent definition.
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