Increasing capacity utilisation through storage virtualisation

In order to manage this exorbitant growth, companies often throw new disk at the problem. Subsequently senior IT managers are bombarded with requests to spend hundreds of thousands of dollars on new storage.

In the past companies have purchased far too much storage in an attempt to ensure that peak performance and availability requirements are met. This approach leaves systems greatly under-utilised. Buying new disk seems like the simple solution until they realise the costs of deploying and managing the storage. Through storage virtualisation these utilisation rates can be dramatically increased, resulting in lower total cost of ownership.

Anyone keeping track of storage technology can't help but come across storage virtualisation at nearly every turn. But what is storage virtualisation? Possessed of certain virtues or capabilities; effective in respect of inherent natural qualities or powers; capable of exerting influence by means of such qualities.

Or to put it another way any abstraction of a thing that retains the power to do what the original thing was designed to do. And that's exactly what storage virtualisation does. It abstracts storage across the enterprise and does the same job an attached storage device would do for a specific server.

Storage virtualisation is the process of taking multiple physical storage devices and combining them into logical storage devices or units that are presented to the operating system, applications, and users.

Storage virtualisation builds a layer of abstraction above the physical storage so as to not tie data to specific hardware devices, providing a flexible storage environment. It simplifies the management of storage and can potentially reduce costs through better hardware utilisation and consolidation.

An application can use, request and change available storage based solely on its required attributes, without regard for, location, physical organisation, or media type. Ideally, this should work in a completely heterogeneous environment, which includes multiple vendors and platforms for servers, software, network elements and storage devices. Storage virtualisation can ease the management of server and storage resources whatever architecture (DAS, NAS, SAN) is chosen by the customer.

Traditionally servers each had internal disk and, in cases of applications needing large data stores, direct attached arrays. In this scenario, the server can only access data in the storage device to which it is attached, and conversely, the storage is only accessible by that particular server.

Typically, some servers such as those used to run an order tracking database or e-mail experience much more traffic and capacity growth than say an HR database. However, the direct attached storage model does not allow re-provisioning of resources from under utilised systems to those about to run out of capacity. Therefore, new storage must be added to the busiest servers to avoid downtime that will occur when out-of-space conditions are encountered.

Faced with the problem of certain servers having abundant capacity while others are constantly at maximum capacity, companies turned to storage networking which allows servers to share storage resources. However, in large environments resource sharing alone is not enough. The cost to manage thousands of disks, now accessible by multiple servers, is a daunting task.

Storage virtualisation allows companies to chose the storage devices that best meet their needs, and then carve up these physical devices into logical volumes to provide resource as required. Combining storage virtualisation with storage resource management allows IT staff to visualise and monitor all the resources on the network, plan for capacity growth, and allocate resources according to business priorities.

Virtualisation Enables Better Control
Higher levels of abstraction enable successively better views for control, which in turn can enable a business to control its IT infrastructure to its advantage. Storage virtualisation allows a business to pool storage sourced from different vendors. Storage combined logically and using a single management product in one location can enable system or storage administrators to control far more storage more easily and with less chance for error than would otherwise be possible. Because storage had to be pre-allocated to specific applications storage networking and virtualisation provides better storage usage resulting in significant cost savings.

Policy-Based Management
If storage can be viewed and managed from a single place, then software policies can also be created for storage and for files to automate many monotonous and demanding, tasks. Managing storage resources and responding to events or assuring, enforcing, and verifying business policies on files can be automated.

Virtualisation and the need for improved storage management go neatly together. Virtualisation enables enterprises to utilise its storage assets to the utmost and allow administrators a greater control, improved storage management gives administrators the tools they need to exercise such control most effectively.

Because storage administrative costs and the value of data are increasing, modern policy control engines improve planning, administration and business control. Improved, automated policy-based storage addresses the problems for the enterprise by reducing the escalating cost of managing both storage administration and that vital data.

Virtualisation Means Intelligent Software
Interestingly intelligent software is what makes virtualisation work. Vendors in the storage and storage management marketplace are striving to create and sell intelligent software and provide the functionality desired in the marketplace.

The most respected and successful hardware storage system vendors appear to be attempting to reinvent themselves as software vendors. Storage virtualisation creates logical pools of storage out of more or less diverse physical storage. Storage virtualisation can also achieve any to any remote mirroring, point-in-time copying, user-preferred or vendor-specific facilities for remote mirroring or point-in-time copying and provide storage management, storage resource management and storage planning capability

Conclusion
Today data and information are among the principal assets of an enterprise. Businesses survive by using its information intelligently to serve customers most effectively. Storage virtualisation helps organisations save on purchasing expensive disk storage when they already have an abundant supply. Through better utilisation of storage resources, IT staff will not be blind-sided by new requests for storage.

Instead, organisations can proactively manage their storage purchasing decisions. At the same time management of growing data stores can be centrally managed, saving time and labour costs. Because VERITAS's storage virtualisation solutions are designed to simplify storage management, efficiently utilise resources, achieve optimal performance, and protect IT investment through flexibility of choice, they help organisations adapt to changing business requirements.

The network now serves as both the processor and the storage, both are available as distributed logical elements. Storage Management has become centred on an organisation's data and information and has proven virtualisation as being necessary, but not self-sufficient.