Software-defined storage is a term that has been used and abused by many vendors. Because software-defined storage is currently defined in so many different ways, consider the following quote from VMware:
- Software Defined Storage is the automation and pooling of storage through a software control plane, and the ability to provide storage from industry standard servers. This offers a significant simplification to the way storage is provisioned and managed, and also paves the way for storage on industry standard servers at a fraction of the cost. (Source: http://cto.vmware.com/vmwares-strategy-for-software-defined-storage/)
A software-defined storage product is a solution that abstracts the hardware and allows you to easily pool all resources and provide them to the consumer using a user-friendly user interface (UI) or API. A software-defined storage solution allows you to both scale up and scale out, without increasing the operational effort.
Many hold that software-defined storage is about moving functionality from the traditional storage devices to the host. This is a trend that was started by virtualized versions of storage devices such as HP’s StoreVirtual VSA and evolved into solutions that were built to run on many different hardware platforms. One example of such a solution is Nexenta. These solutions were the start of a new era.