Making the move to utility storage: overcoming the crisis of complexity

Computer Technology Review, Nov, 2004 by Craig Nunes

The premise sounds great: Enterprise storage so simple that it works just like any other utility. Like flipping a light switch, storage is to be accessed on demand while you only pay for the capacity actually used. But is it really possible?

Increasing pressures to decrease costs and improve efficiency within data centers have meant that IT executives must find alternatives to traditional storage solutions. CIOs are looking for a path forward, but concrete examples of companies making the move to a utility-like environment are difficult to find.

The good news: To gain a competitive advantage, many innovative companies have already implemented successful Utility Storage solutions, realizing tangible benefits from vastly simplified and consolidated storage environments that are highly scalable and easy to manage.

Utility Storage solutions are ideal for storage consolidation, utility computing and performance-intensive application environments. Utility Storage is the storage cornerstone of utility computing, which leverages server and storage virtualization technologies to dramatically improve efficiency and utilization.

The Problem with Traditional Solutions

A crisis of complexity: Not all virtualized environments are created equal. In an effort to utilize information more effectively, organizations are pursing physical and logical storage consolidation. In the process, they often add extra layers of hardware and software to their storage architectures. This add-on functionality is often located on hosts, switches, or separate appliances. Examples include non-array-based volume management, storage resource management, information lifecycle management (ILM) and virtualization software. Other examples include separate storage array architectures for different quality of service solutions, multiple storage arrays within each class of service, and continually sprawling switch fabrics. The result is a seething crisis of complexity.

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Underutilization: Compounding this crisis is the problem of underutilization. For example, for any unique data that an organization possesses, the amount of storage capacity that has to be purchased to store, share and protect that data is often much greater than necessary. As a 2003 industry study by Glasshouse Technologies demonstrates, the average utilization rate of storage environments is approximately 25%. Table 1 illustrates the potential effects of this inherent inefficiency.

Unfortunately, the inefficiencies in traditional storage arrays do not stop at resource utilization. They extend to IT operations as well, including storage administration.

Operational Inefficiency

Today, basic tasks associated with storage administration include:

* Preconfiguration of storage array capacity

* Initial storage provisioning that includes multiple steps within the array, in the network and on host servers

* Subsequent volume expansion

* Ongoing storage-related performance management and optimization

* Backup, restore and recovery to and from tape

* Storage capacity planning and monitoring

Most of these tasks can take hours or even days of administrators' time and may require weeks of training to develop the specialized skills required. This restricts the ability of IT to quickly and flexibly address new organizational demands that could create a substantial return on investment.

There Has to Be a Better Way

In effect, organizations choosing traditional storage arrays are purchasing four times as much usable capacity--up to eight times as much raw storage capacity--as is necessary to support the unique data created and written by applications and end users. The inefficiencies seen within many of today's enterprise storage solutions have been mirrored more broadly across the overall IT environment. Examples include the under-utilization and management overhead associated with server resources. Clearly, it's time for a new, simpler way. This is where Utility Storage comes in.

Utility Storage: A New Approach

Utility Storage takes the best of modular storage array design and enables it to scale massively, beyond today's high-end monolithic arrays, without performance degradation or management overhead. It adds "in-system" fine-grain virtualization such as thin provisioning and centralized volume management to eliminate poor resource utilization and operational inefficiencies. Finally, it adds granular instrumentation to provide accurate usage assessment and chargeback. It allows organizations to manage storage without thinking about it; to get as much as they need, only when they need it; and pay only for what they use, when they use it.

Making it Simple: Thinking Thin

Thin provisioning is a key Utility Storage feature that eliminates the inefficiencies producing poor utilization results within traditional storage arrays. Thin provisioning is based on dedicate-on-write technology, as opposed to the traditional dedicate-on-allocation approach. This means that, during the initial provisioning activity, an administrator can allocate as much storage as an application is likely to consume over its lifetime. However, the thin provisioning approach only allocates physical storage capacity to a specific volume as an application actually writes data to it. As the application continues to write data, the system will continue to draw additional storage capacity from the common free space pool to service the volume. This dedicate-on-write approach drives up utilization efficiency to nearly 100% (Figure 1).