One of the major trends in IT storage today is the accelerating growth of software defined storage (SDS). According to market research firm MarketsandMarkets, the market for SDS products will grow from $4.72 billion in 2016 to $22.56 billion by 2021. That’s an outstanding compound annual growth rate (CAGR) of 36.7%.
But many IT leaders, even storage professionals, remain unsure of exactly what the term SDS really signifies.
Actually, that confusion is not surprising. As with many new technologies that begin to expand their market share, some storage vendors have taken the opportunity to break out the software component of existing products and call it SDS. And, of course, their definition of SDS just happens to precisely match the feature set of the product they are trying to sell.
Contrary to what some skeptics claim, however, SDS is much more than just the latest marketing buzzword. In fact, many proponents see it as the vanguard of a revolutionary advance in how enterprise storage is managed and delivered.
The Storage Networking Industry Association (SNIA) defines SDS as “virtualized storage with a service management interface.”
Although storage virtualization has been in use for some time, SDS takes it to a new level. The distinctive feature of SDS is the decoupling of the intelligence of the storage system from the underlying hardware. This means SDS is storage-agnostic – it isn’t tied to any particular type of hardware or media. Instead it treats all the devices it controls, whether spinning disks, flash memory arrays, or even entire SAN or NAS subsystems, as part of a single storage pool. Users and applications (via standard APIs) can access storage through a consistent software interface without needing to have any knowledge of what hardware is actually storing the data.
One of the major benefits of the storage heterogeneity SDS allows is that costly special-designed storage appliances are not required (though, of course, they can be used if desired). Instead, inexpensive commodity hard drives attached to x86 hosts can be used, mixed in with higher performance technologies such as flash memory arrays as necessary. The SDS software has the intelligence to use tiering and caching functions to dynamically assign particular sets of data to the appropriate storage devices based on the performance demands of the workload being run.
The result of hiding all the storage hardware behind the SDS software interface is that flexibility, scalability, and control are maximized, while costs for hardware, maintenance, and storage management are minimized.