First of all, Software-Defined Storage provides abstraction of storage characteristics from the underlying hardware. This means that SDS solutions can run on commodity server hardware with x86 processors, enabling cost savings over traditional storage area network (SAN) and network-attached storage (NAS) systems, which tightly couple software and hardware.
With SDS, storage management becomes unified and much easier as all storage resources are pooled together and orchestrated at the OS or Hypervisor layer with the help of virtual storage controllers running on every cluster node. Ultimately, you can provide your applications with all the necessary resources, including compute, memory, storage, and networking, via a single management interface.
By separating the storage hardware from the software layer, Software-Defined Storage allows companies to purchase different storage hardware pieces from various vendors. Thus, SDS breaks the spell of vendor lock-in and eliminates such issues as under- or over-utilization of storage resources and interoperability problems.
One of the greatest benefits of SDS is that it provides your current storage infrastructure with features which were previously unavailable. These include deduplication, replication, snapshotting, server-side caching, and log-structuring across a wide range of server hardware components. To say more, SDS makes your IT infrastructure more flexible. It allows the system to both scale up by simply throwing in more capacity to the existing storage nodes, or to scale out by adding new nodes with their own storage, RAM, and CPUs to increase both capacity and performance.