Virtualisation technology, which offers users the ability to pool their hardware resources, is playing a major role in making IT more flexible and cost-effective.
Virtualisation software has allowed many users to reduce their hardware assets, or use them more efficiently, by running multiple “virtual machines” side by side on the same hardware, emulating different components of their IT systems.
Virtualisation has now moved beyond mainframes and servers and has found its way into applications, networks and storage, among others.
Galen Schreck, senior analyst at Forrester Research, said mainframe users were the first to adopt server virtualisation. In fact, the technology has been around for decades.
Following the mainframe, Unix suppliers such as IBM, Sun Microsystems, and Hewlett-Packard began offering virtualisation technologies. “These have matured into their current line-ups of logical partitions, Solaris containers and Virtual Server Environment, respectively,” Schreck said.
More recently, VMware’s ESX Server, Microsoft’s Virtual Server, and open source supplier XenSource’s Xenenterprise have lowered the cost of virtualisation because they run under Windows and Linux, and on commodity Intel or AMD x86 servers.
“Many firms attribute their adoption of virtualisation to server consolidation, but an equivalent number are using the technology to make their server environments more flexible and agile in a manner once exclusive to Unix-based platforms,” Schreck said.
Users are beginning to reap a range of benefits from virtualisation which go beyond the cost savings of server consolidation.
For example, the Association of Teachers and Lecturers (ATL) is using virtualisation to not only cut hardware costs, but also to recover quickly from systems failures and maintain business continuity.
The ATL is using VMware’s ESX Server virtual environment and its VMotion tool. VMotion can move an entire virtual machine instantaneously from one server to another, and makes use of virtual storage, applications and networking. The network is also virtualised by ESX Server, so the virtual machine retains its network identity and connections after the migration process.
Ann Raimondo, head of IT at the ATL, said virtualisation has halved the association’s server count from 22 to 11 through consolidation, cut its operational expenses and capital costs, and has given it a single view of all its computing resources.
Virtualisation has also allowed the ATL to restore systems quickly after a failure because they are backed up to servers rather than tapes stored at an off-site datacentre. The virtualisation technology can virtualise processors, network interface cards, ports and discs, so a back-up can be up and running in minutes.
Another common use of virtualisation is to test and develop applications in a secure environment without affecting the main IT systems. HM Revenue & Customs is using a software virtualisation platform to simplify and accelerate the deployment of about 600 wide-ranging applications used by its 70,000 employees.
HMRC’s main reason for deploying its virtualisation platform – Softricity’s Softgrid, running on HP hardware – is to reduce its testing and deployment costs and to port its applications over to a Citrix thin-client system.
The big drawback of virtualisation is that users could face serious performance issues, as fewer servers do more work. Although virtualisation technology lets users operate fewer servers, it does not make programs run faster.
Microsoft, for example, advises users to increase the memory, processors and hard drive speed of their servers, and make other technical adjustments to compensate for the additional workloads that virtualisation creates.
Virtualisation also means licensing issues. The technology allows applications to run independently of the hardware, which can contravene some licence agreements.
Neil Macehiter, partner at analyst firm Macehiter Ward-Dutton, said, “Server virtualisation is undoubtedly forcing software suppliers to reappraise their licence models. The licensing models of many software suppliers do not allow for flexibility.”
But there are signs of change from the supplier community. At the end of last year, Microsoft allowed users of Windows Server Enterprise and Datacenter to run up to four instances of the software under products such as VMware Server and ESX Server at no additional cost.
However, this permission does not cover older Microsoft operating systems. In fact, users would be wise to check the terms and conditions of their other operating systems and applications before they virtualise them.
But in the face of the technology’s potential benefits, these obstacles appear minor: it looks as though virtualisation is here to stay.
Case study: HBOS banks on virtualisation
Banking group HBOS launched a massive virtualisation strategy in 2003 that will eventually virtualise storage, local area networks and application servers.
HBOS’ IT decision was driven by business requirements, which included supporting business growth and controlling and reducing IT costs through optimisation, integration, virtualisation and automation.
HBOS virtualised its wide and local area networks first, then reorganised its application servers by using Microsoft Virtual Server to virtualise its IBM Aix mainframe and HP Windows/Itanium servers.
HBOS is reordering 1.7 petabytes of storage to access and manage the space as virtual pools of resources. To do this, the bank is implementing Emulex’s Lightpulse LP11000 host bus adapter (HBA) equipment, along with Virtual Storage Manager software and storage systems from StorageTek.
The HBA is a key part of the virtual storage system. It sits on the host server to control the transfer of data between the host and the target storage device in an intelligent way.
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