Essentially, storage virtualization involves the introduction of an abstraction layer between storage consumers (both individual users and servers of all shapes and sizes) and physical storage devices. This abstraction layer permits much greater freedom in managing very large storage infrastructures by allowing administrators to transparently replicate and migrate data without storage consumers being aware of it. Storage virtualization also provides nearly limitless capacity and performance scalability.
The newest entrant to the primary storage field is not so much a new form of storage hardware or software, but an entirely different storage delivery model. Instead of buying a storage device that's suited to your organization's needs and then inevitably upgrading it in phases as you grow, the promise of cloud-based storage is that it allows you to pay for the storage you're using when you're using it and to elastically scale without limits.
Though cloud-based storage is not widely used by enterprises, few doubt that it will mature and ultimately play a huge role in the future of storage. Current challenges include convincing customers that cloud-based alternatives are reliable enough to support the mission-critical needs of the enterprise -- service-level agreements tend to be less than reassuring -- and surmounting the security and regulatory hurdles that arise when sensitive data is stored with a third party.
This article, "The six levels of primary data storage," originally appeared at InfoWorld.com. Read more of Matt Prigge's Information Overload blog and follow the latest developments in network storage and information management at InfoWorld.com.