Software-defined storage (SDS) creates a virtualized network of storage resources by separating the control and management software from the underlying hardware infrastructure. This can be used to create storage networks that may tie together large pools of storage resources that can appear as one virtual entity.
A form of software-defined everything (SDx), storage virtualization is analogous to software-defined networking (SDN) for storage technology. Often storage resources are kept on separate networks, known as storage area networks (SANs), requiring different management software and platforms.
Software Defined Storage
An SDS system has several important components that separate it from traditional SANs. The Storage Network Industry Association (SNIA) has made an effort to describe important characteristics first defined software-defined storage (SDS) to include:
- Automation– Simplified management that reduces the cost of maintaining the storage infrastructure
- Standard Interfaces – APIs for the management, provisioning, and maintenance of storage devices and services
- Virtualized Data Path – Block, File and/or Object interfaces that support applications written to these interfaces
- Scalability– Seamless ability to scale the storage infrastructure without disruption to the specified availability or performance
- Transparency – The ability for storage consumers to monitor and manage their own storage consumption against available resources and costs
(Source: SNIA – www.snia.org)
SDS can share other characteristics of the SDN movement, including the use of common, open management interfaces and a reliance on DevOps-style application development and management. The goal is to create a centralized storage brain that can manage, monitor, and automate the storage activities for a software-defined data center.
The Storage Brain of the Cloud
The advent of Software-defined storage is changing the storage industry, just as SDN has changed networking. To date, storage has been based on a wide variety of storage software, hardware components, and storage-area networking (SAN) components. Large vendors such as EMC, IBM, and NetApp have built multi-billion-dollar businesses selling specialized storage and SAN components. However, a number of startups have taken advantage of the SDX movement to push more software-based solutions. Startups such as Atlantis Computing, Coho Data, and Nutanix are building software and hardware systems targeted at virtualized data centers and SDS environments.
The latest trend in storage and SDS is to build a network of simple, massively scalable hardware arrays – whether they be flash storage, hard drives, or combinations – and connect them together with an SDS system so that more storage can always be added by easily snapped in by adding hardware. This is known in the business as a “scale-out” architecture.