Storage Centralization.
The business and technical justification of storage centralization have long been known and are addressed through the replacement of discreet captive storage with centralized storage arrays. Captive, non-centralized storage is expensive to procure, maintain, and manage. Central storage creates its own set of issues related to ownership, management control, and provisioning.

Storage ownership.
A common enterprise level problem with storage centralization has to do with asset ownership. Ownership issues frequently arise when business different groups procure assets through the budget process. The biggest problem with this approach is the creation of discreet storage islands within the IT environment. Sharing the underlying asset becomes problematic due to security or a lack of chargeback capabilities that could enable sharing. Replication may be required but becomes so expensive that valuable data is inadequately protected. The result is frequently over-provisioning, under-utilization, and a major management problem. Each of these problems adds  potentially avoidable cost.

Over-Provisioning/Under-Utilization.
Over-provisioning is a common, almost universal problem in enterprise IT. At each stage of the procurement cycle, various groups innocently add to the problem: Business groups frequently over estimate; DBAs and storage administrators add their own ‘fudge factors’ in an attempt to reduce future touch points to applications, databases, and storage management. The result is under-utilization, over-provisioning, and inordinate costs.

Security issues related to shared resources.
Yet another problem has to do with resource sharing. Resource sharing is a key concept in consolidation and must be done in such a way that each business group is assured of both security and access to their underlying data.

The need for Storage Virtualization.
What is required is the delivery of storage or infrastructure that is more closely identified with the client service. Service delivery requires the use and implementation of storage virtualization techniques. Storage virtualization is the concept of individualized service delivery from a large, centralized pool of storage. In order to accomplish this, a storage array must be capable of delivering the following virtualization services to the enterprise.

*Secure Multi-Tenancy. *

Secure multi-tenancy refers to the capability of the centralized asset to house, support, and deliver service to a multitude of diverse clients. Each client’s data is sacrosanct; data is logically segregated and discreet from all others on the same platform. This virtualization technique allows for greater security, easier management, and closer alignment of resource to service.

Thin Provisioning/Just in Time Procurement.

Thin provisioning is the concept of creating storage sizings that more closely resemble the estimated sizing to the actual. When a procurement request goes through, storage is provisioned in smaller increments that are automatically enlarged as required. At any given point in time, storage utilization is kept at optimal levels, effectively managing the relationship between storage required and procured. Thin provisioning can have a dramatic effect on capital acquisition, procurement cycles, and ongoing support and management. Migration from existing non thinly provisioned storage to thinly provisioned storage can have return on investment rates of 50% or more, and pay back rates of less than one year.

Replication
Replication is fundamental to data protection. Local replication (such as snapshots) and geographic replication (both Synchronous and Asynchronous) allow for management of Recovery Point and Recovery Time Objectives. Replication is expensive and adds complexity to the enterprise; Not only are multiple copies of data made, networking and management costs add to the financial burden. Managing replication costs are a key component of IT management.

Management
Virtualized services require a higher level of management, which must by necessity come in the form of management software tools. An individual storage manager/administrator should have the ability to manage hundreds of terabytes of assets, which can only be accomplished through the procurement and use of management software, standardization, and consolidation.