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Internal storage cloud defined
You could say an internal storage cloud is the same as a public storage cloud -- storage delivered as a service over the network -- except the components of an internal storage cloud sit behind the firewall. But even that definition isn't completely accurate. A public storage cloud provider, for instance, can reserve a portion of its capacity for the exclusive use of one customer, making it a private storage cloud although it's not internal to the customer (see "Different types of storage clouds," below).
|Different types of storage clouds|
Public storage clouds. Services like Amazon's Simple Storage Service (S3) and Nirvanix Inc.'s Storage Delivery Network make massive amounts of file storage available at low cost. Multi-tenancy allows the providers to keep each customer's storage and apps separate and private. Portions of the public storage cloud can be carved out to create what amounts to a private storage cloud.
Private storage clouds. With a private storage cloud, a company owns or controls the infrastructure and how applications are deployed on it. Private clouds may be deployed in an enterprise data center or at a co-location facility. Private clouds can be built and managed by a company's own IT organization or by a service provider.
Internal storage clouds. This type of storage cloud is similar to a private storage cloud except that it remains inside the organization's firewall. It may be built with the help of consultants or integrators, but it's hosted and maintained by the IT department.
Hybrid storage clouds. A hybrid storage cloud combines attributes of both public and private/internal clouds. It's mainly used to access on-demand, externally provisioned capacity on a temporary basis. The ability to augment a private or internal cloud with capacity from a public cloud can help a company maintain service levels in the face of rapid workload fluctuations or planned workload spikes. Hybrid clouds, however, introduce the complexity of determining how to distribute applications across both a public and private cloud.
Source: Sun Microsystems Inc.
Rather than specifically define the internal storage cloud, industry analysts and consultants prefer to describe its attributes.
This was first published in October 2009