15 September 2008 Features

 

IT & Ops 3: Head in the cloud

Martin Banks

Virtualisation can triple the workload a server can handle and is paving the way for utility services.

In just a couple of years, virtualisation has become one of the most widely used IT industry buzzwords. Google, for example, found ‘about' 22.5 million mentions in just 0.06 seconds. It has some significant benefits for users - and cost-conscious ones in particular - but it is also a major enabling technology for the next round of systems and operational developments. The primary one, already receiving its fair share of hype, is ‘The Cloud'; and that is arguably just a precursor of a further big technology development - utility services. virtualisation is, in its own way, playing a major role in what will become a significant change in the way users plan the provisioning of their IT services and resources.

The obvious advantages that spring from virtualisation technologies are based around its ability to greatly increase the utilisation of available IT resources. It is still the case that the typical server is run at a utilisation level of around 15%. In other words, 85% of the time it is actually doing nothing productive, while costing money being run idle. In addition, the way many current applications are constructed, they need to run on a specified server, or on several if the workload is considered large enough. In practice, this just decreases the overall utilisation level.

Providing technology that allows servers to be partitioned so that multiple, virtual servers can run on the same physical machine has brought performance and financial benefits. As the workload of a given data centre increases, capital expenditure can be reduced and significant savings in energy costs become possible.

In practice, the issue of virtualisation and capital expenditure often includes an initial spend in order to make a greater saving over the medium term. This exploits the continued improvements in server technology that provide step function jumps in performance, coupled with lower energy consumption and systems designs specifically configured to work in virtualized environments. Together, these make it possible to use the increased server performance and virtualisation readiness to at least triple the workload each server can manage. Some estimates suggest that by next year, a typical physical server will be hosting five or more virtual servers.

One key advantage of this is that, because this extra processing capacity is virtual, it does away with the need to buy additional physical servers every time the workload varies. It can be called into play or shut down as required. This gives any fast-moving enterprise such as a bank the flexibility to scale the processing resources in use without involving additional capital expenditure. Normally such increases will be part of a business plan - for example meeting the additional workload required by a marketing program for a new product - and if necessary other workloads can be given a lower priority to accommodate them. It does mean, however, that businesses gain the agility to meet the needs of unplanned or temporary tasks, such as a managing a response to an external crisis or change in market demand at one extreme, through to applications developers wanting to test new code on a parallel live environment running in an isolated ‘sand box'. 

It has not yet happened that an IT manager has been fired for profligate energy consumption, but it may soon: IT systems are now amongst the biggest energy consumers in business and industry, so green issues - both in terms of direct energy cost and the support costs of the associated real estate - are major factors in favour of virtualisation. New servers from the likes of IBM, HP, Sun and Dell are not only being designed to consume less power while offering higher performance, they are also reducing associated costs. Lower power means less heat produced, which means reduced air-conditioning costs per unit of processing work performed. This also means server racks can be more densely packed, reducing the physical space required to contain them (see related article).

These arguments are now being extended backwards into the back office with IBM and its latest mainframe, and forwards to the desktop with a growing range of vendors offering ways of integrating low-cost thin clients that are more cost effective, more secure and much greener than the PC.

IBM's z/10 mainframe is obviously targeted at improving performance and running costs for the many critical back office applications run on such machines. But the company's close involvement with Linux means that with the increased performance of the machine, coupled with improved virtualisation technologies, it will be possible to consolidate a mixed environment of up to 4,000 virtual servers onto a single z/10. IBM is claiming this will bring significant operational savings over x64-based server systems, including an up to 80% reduction in energy consumption, an 85% saving in floor space, and an 80% reduction in associated datacentre labour costs through reduced support requirements. IBM is also claiming that such arguments are now well received in green field markets for the mainframe, such as India, China and Brazil.

The next big thing in virtualisation is likely to be at the user end of the IT environment, with new thin client technologies. The PC has had a long run as the mainstay of the enterprise desktop, and the laptop computer has extended that. But there are growing weaknesses in the arguments in favour of continued PC use. They can no longer be called green, for example, and they offer very poor resource utilisation, create management problems when applications are upgraded, and continue to be the target for attacks on their friable security capabilities.

Using virtualised thin client technologies can cut the power consumed by desktop systems to a minimum, not least because the processing work is performed back at the server, so there is no requirement for large disk drives or memory systems. In fact, Fujitsu Siemens now has a thin client that offers the ultimate ‘sleep' mode, switching itself off completely when not in use, but switching on again automatically when required. This operational model - running the applications at the server end - means that not only are energy and running costs reduced, but capital expenditure is also cut. Sun Microsystems, for example, is already speculating on thin clients having a lifecycle of 20 years or more, as all applications changes and upgrades are managed at the server level. The only aspect that might need to change on thin clients is the browser software, held in a Flash memory chip.

Companies such as Citrix and Wyse have been championing the thin client model for many years, but have now been joined by several others. VMware, for example, has seen the potential that virtualising the client gives in providing an integrated, end-to-end environment while others, such as IGEL Technology, are now targeting the potential of universal thin client software, decoupled from the hardware, that can be easily integrated with a number of different data centre environments and readily switched between a simple equivalent of a dumb terminal and an equivalent to a power user's feature-rich PC without the security risks. The technology can also provide significant jumps in flexibility for the users. For example, it can accommodate smart card technology so that users are not tied to ‘their' desktop. Their card contains the details of their working ‘personality' and can be used on any available client. This can also be used with laptop systems, with suitable security, for staff that travel for work purposes.

Virtualisation's ability to expand the number of virtual servers available, coupled to flexible client systems, is now leading to the growth of The Cloud. This term is being used to define an environment where multiple clients are loosely coupled to multiple data centres so that users can access and use services that are appropriate to their jobs and for which they have access rights. The use of the word ‘services' is important in understanding the conceptual changes associated with The Cloud, as it breaks the traditional model of a user accessing an application running on a specified server. Instead, The Cloud allows users to simply think in terms of requesting and using the services they require - for example the business processes needed to complete a specified task. Those processes could be running on any available virtual server. Normally this will still be in the enterprise data centre, but it does not need to be. It could be running on the servers of a business partner or an external service provider.

This is the model on which Software as a Service vendors such as NetSuite and Salesforce operate, with the code used to build their services running on their data centres. The business queries are, however, generated on, and the results delivered to, customer desktops. The next logical step will be for larger specialists, such as BT, Google, Amazon and Microsoft, to aggregate such services - and many others both small and large - into utility services that enterprises can access as much or as little as required.

Much has been written about utility services becoming as ubiquitous as the electricity supply. In practice, however, while they will become widely available and very rich in service offerings, most enterprises will want to maintain their core business-critical services within their own, internal environments, even if that is a local Cloud. For example, the response times of The Cloud may be too slow for some of the highly time-critical transaction management processes banking is famous for. They will, however, also use external service providers for many non-critical services, as this will become the more cost-effective option.

For the banking community, virtualisation is the first step along a path that combines greater operational flexibility and agility, the ability to grow both quickly and under control, better value and ROI, end-to-end comprehensive management (including issues such as good governance and compliance) and much greater freedom to choose how the processes and services that make up the business are delivered to staff, business partners and customers. BT