Software defined storage (SDS) is much different from software-based RAID and is really the separation of the data plane from the data control plane and the introduction of an API to manage and provision the storage. The ability to use reprogrammable hardware or standard servers allows for greater flexibility and agility. Leveraging the data control plane operators or systems can control the behavior of the storage systems dynamically. This becomes very valuable and powerful in instances of storage as a service and cloud automation.
This is not a universal truth. It is also not true that software defined storage has to be sold or licensed as a software only solution. Some software defined storage solutions are less specific about the hardware they will operate on than others. However, a software defined storage appliance may leverage specific reprogrammable hardware to provide greater efficiencies and higher performance. The use of a Field Programmable Gate Array (FPGA) or chipset specifically designed for a specific workload may be more cost-effective in the long run. Software defined networking solution providers are doing something similar in many cases and at scale has proven to be a cost savings over ASIC’s and generic x86 compute alone.
In addition to abstracting physical resources, Software Defined Storage systems need to offer policy-based automation for resource provisioning and management as well as the ability to programmatically control storage through an API. This will allow cloud orchestration solutions such as OpenStack, CloudStack, or vCloud to operate at scale.
Software Defined Storage is still a term that is evolving and a definition that will become more finite as more products come to market. While software defined storage has been around for many years, it is still in its infancy as a technology. The value of software defined storage will become exponentially greater as more enterprises begin to understand how to use it and more tools and solutions are built-in a way that leverages the true strengths and benefits of software defined storage. Software defined storage will make its biggest impact on organizations implementing private and public clouds.