With the wave of virtualisation sweeping across the business IT infrastructure, Mark Galpin, product marketing manager of Quantum, encourages IT managers to embrace the advantages of virtualisation after fully considering the impact on the back-up and recovery infrastructure.

There can be no doubt that virtualisation is the technology trend of the moment.

Google the term and more than 30 million links offering expertise in the area will appear in milliseconds – and this is not just more technology hype.

The virtualisation trend is having an impact on the business IT landscape.

Drivers for virtualisation range from hardware, power and space savings through to increased manageability and data protection.
Analyst group Forrester reports that 23 per cent of European firms are today using server virtualisation, and an additional 12 per cent are piloting the process as a means of reducing costs.

IDC also predicts that the total number of virtualised servers shipped will rise to 15 per cent in 2010, compared to 5 per cent in 2005.

And with the recent flotation of virtualisation leader VMware at a market value of GBP£9 billion, many investors as well as IT experts are betting their business on this trend becoming accepted everyday best practice.

Virtualisation brings benefits

Virtualisation has brought us new ways of doing things from managing desktop operating systems to consolidating servers.
What’s also interesting is that virtualisation has become a conceptual issue – a way to deconstruct fixed and relatively inflexible architectures and reassemble them into dynamic, flexible and scalable infrastructures.

Today’s powerful x86 computer hardware was originally designed to run only a single operating system and a single application, but virtualisation breaks that bond, making it possible to run multiple operating systems and multiple applications on the same computer at the same time, increasing the utilisation and flexibility of hardware.

In essence, virtualisation lets you transform hardware into software to create a fully functional virtual machine that can run its own operating system and applications just like a “real” computer.

Multiple virtual machines share hardware resources without interfering with each other so that you can safely run several operating systems and applications at the same time on a single computer.

The VMware approach to virtualisation inserts a thin layer of software directly on the computer hardware or on a host operating system. This software layer creates virtual machines and contains a virtual machine monitor or “hypervisor” that allocates hardware resources dynamically and transparently so that multiple operating systems can run concurrently on a single physical computer without even knowing it.

However, virtualising a single physical computer is just the beginning. A robust virtualisation platform can scale across hundreds of interconnected physical computers and storage devices to form an entire virtual infrastructure.

By decoupling the entire software environment from its underlying hardware infrastructure, virtualisation enables the aggregation of multiple servers, storage infrastructure and networks into shared pools of resources that can be delivered dynamically, securely and reliably to applications as needed. This pioneering approach enables organisations to build a computing infrastructure with high levels of utilisation, availability, automation and flexibility using building blocks of inexpensive industry-standard servers.

Benefits can come with initial increased complexity

One of the great strengths of virtualisation is its apparent simplicity and its ability to simplify and increase flexibility within the IT infrastructure. However, as time passes there are some important lessons emerging from early adopters’ experience which are important to consider.

IT managers looking to unleash virtualisation technology in their production networks should anticipate a major overhaul to their management strategies as well. That’s because as virtualisation adds flexibility and mobility to server resources, it also increases the complexity of the environment in which the technology lives. Virtualisation requires new thinking and new ways of being managed, particularly in the back-up and recovery areas of storage in a virtualised environment.

Virtual servers have different management needs and have capabilities that many traditional tools cannot cope with. They can disappear by being suspended or be deleted entirely, and they can move around and assume new physical addresses.

As a result, some existing infrastructures need to become more compatible with virtual machines in areas such as back-up and recovery.

Many of the virtualisation deployments to date have been implemented on application or file servers where unstructured data is the key information. In these environments, VMware tools for back-up and recovery work well. Copies of the virtual machine images can be taken once a week, moved out to a proxy server and then saved onto tape in a traditional manner.

Real returns available through virtualising structured data

But the real returns on investment for business from virtualisation will come in its ability to virtualise the structured data of its key applications such as Oracle, SQL or Exchange. Many of these areas have been avoided to date because of the complexity of protecting these critical business applications in a virtualised environment.

The standard VMware replication tools take a snapshot image in time and do not provide a consistent state for recovery and rebuild of structured data.

The answer for critical applications where recovery times need to be seconds rather than hours is to build expensive highly available configurations. This solves system or site loss risks but protection is still required against data corruption, accidentally deleted data and virus attack.

Less critical systems also need to be protected and data sets retained for compliance and regulatory purposes. In most data centres, traditional backup and recovery will be performing these functions today using familiar software tools that integrate with the database and tape or disk targets for the data.

So, the obvious solution is to continue to back-up everything as before but in a virtualised environment the increased load on the network infrastructure would become unbearable very quickly with machines grinding to a halt and applications groaning.

Tape systems with their high bandwidths and intolerance of small data streams are also unsuitable as targets as more flexibility is needed to schedule back-ups to multiple devices.

The answer is disk-based back-up appliances

With structured data, the answer is to use new disk-based back-up appliances to protect data. Using a Quantum DXi solution, for example, businesses can combine enterprise disk back-up features with data de-duplication and replication technology to provide data centre protection and anchor a comprehensive data protection strategy for virtualised environments.

DXi solutions bring a number of additional benefits. In as much as they are useful when storing structured data, they are also effective in storing virtual machine disk format (VMDK) images and unstructured data, meaning users can benefit from a single point of data management. A benefit of storing VMDK images on de-duplicated disk is that all VMDK image are very much alike and so achieve an exceptionally high de-duplication ratio. This means much larger volumes of data can be stored on limited disk space.

The DXi range leverages Quantum’s patented data de-duplication technology to dramatically increase the role that disk can play in the protection of critical data. With the DXi solutions, users can retain 10 to 50 times more back-up data on fast recovery disk than with conventional arrays.

With remote replication of back-up data also providing automated disaster recovery protection, DXi users can transmit back-up data from a single or multiple remote sites equipped with any other DXi-Series model to a central, secure location to reduce or eliminate media handling. DXi–Series replication is asynchronous, automated, and it operates as a background process.

Whether businesses are looking to increase return on investment from their virtualisation implementations or planning a virtualised environment, the lessons are clear. To make the most of this latest technological innovation, IT managers must plan their recovery and back-up strategies to cater for the virtual new world.

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