It is virtually impossible to avoid the hype surrounding Virtualisation. It is perceived as the hottest theme of IT at the present moment which seemed to have reached a crescendo in 2006.
The “V” word has been thrown around a lot in recent times. IT vendors have been promoting it as a type of silver-bullet to solve many pressing IT problems. Is server sprawl a problem? Virtualize! Storage issues? Virtualize! Want to streamline network management? Virtualize! Know how to smooth software testing and deployment? Virtualise!
At times it sounds like oversell, not least because the word itself is being applied to such a broad range of technologies. There are virtual machines, virtual memory, virtual networks, virtual storage, operating system Virtualisation and much more. In addition, terms such as utility computing and grid computing involve computing strategies that aim to virtualize resources.
Much of the clamour is arising because advances like multi-core processors and 64-bit operating systems that are driving fundamental change in the x86 server environment. But Virtualisation extends to all parts of the IT infrastructure and beyond, and this ubiquity can create confusion. What exactly does Virtualisation mean, what technologies does it refer to and where is it best applied?
Defining the “V” Word
As a general definition, Virtualisation refers to abstracting, or masking, a physical resource to make it appear different logically than it is physically. All forms of Virtualisation share two common characteristics. First, as it abstracts the physical resource, it also enables the resource to be pooled and/or shared. Second, it creates a management layer or control point for the virtualized resource.
The result is that Virtualisation technologies offer capabilities that can increase resource utilization, availability and productivity. It can also assist with consolidation projects, which can reduce costs for IT resources and in terms of the infrastructure (power and cooling). By decoupling the tight linkage between application and infrastructure, it can make IT more flexible and easier to change.
This is not just hype. Virtualisation technologies are already embedded into the IT infrastructure of leading Asia-Pacific enterprises, as well as many smaller businesses, and this trend will continue.
For example, IDC has predicted a dramatic future for server Virtualisation. The market intelligence and research organization stated in Server Virtualisation Market Forecast and Analysis, 2005-2010 that just over fifteen percent of new operating systems deployed in 2005 – counting all Windows, Linux, UNIX and other licenses – ended up on virtual machines. Yet, IDC forecasts that by 2010, more than 40 percent of new operating systems deployed will be on virtual machines.
While much of the current Virtualisation buzz concerns servers, resources can also be virtualized within the network, software and storage layers. With so many potential control points, IT managers and staff need to be aware of how each layer interacts with other management control layers, how this complexity can be handled, as well as any potential issues.
Software Virtualisation
Numerous examples exist of ways that the platform software layers (applications and operating systems) provide virtualized solutions in today’s data centers. For example, a pre-emptive multitasking operating system shares the processor across different applications, making it appear as if all are running simultaneously.
Virtual machines are an extension of this concept, in which software abstracts a server’s physical resources (processors, memory and I/O) to share the hardware across multiple instances of the operating system. This makes it appear as if multiple operating systems are running simultaneously on different hardware.
Virtual machine software is one of the most common examples of software abstraction today. Its ability to share and automatically distribute the supply of resources can assist companies to consolidate and make greater use of existing infrastructure.
Yet, Virtualisation also creates its own challenges. One issue is increasing management complexity. If left unaddressed, this can lead to virtual machine sprawl- uncontrolled flexibility that defeats the objectives of Virtualisation.
Network Virtualisation
Virtual local area networks (VLANs) are one example of how Virtualisation can occur in the network layers. Ethernet VLANs allow a network administrator to define logical groups of network-attached end devices including printers, storage or compute nodes (for example, servers, workstations or clients).
The administrator can provide separate virtual LANs that logically isolate one group of nodes from another. For example, this may mean setting up all servers, switching ports or users related to marketing on one VLAN and setting up all accounting servers on a different VLAN. Even though both may exist on the same physical network, the VLAN controller in the switch masks the physical attributes of the network by keeping the two VLANS logically isolated.
On the other hand, a VLAN can also define virtual domains that communicate as if they were on the same physical network, even if they are physically located on different Ethernet segments. The use of virtual segments allows multiple physical segments to behave logically as if they were a single network domain.
Storage Virtualisation
Like other forms of Virtualisation, storage Virtualisation is the gathering of physical storage resources into a unified pool that can be used by applications, desktop clients, or other types of storage clients.
Commonly used in a SAN and managed from a central console, Virtualisation can reduce many of the tedious, time-consuming aspects of managing storage devices. Storage Virtualisation helps storage administrators perform backup, archiving, and recovery tasks more easily, and in less time, by disguising the actual complexity of the SAN.
Because storage vendors differ in their Virtualisation strategies, it is important to consider the approach and strategy of each. One aspect to be wary of in single vendor SAN environments is that scaling out can mean facing vendor lock-in. In heterogeneous or multi-vendor SAN environments, competing standards and incompatible technologies can create challenges, particularly when, for example, data needs to be migrated between an aging system and a new one.
In both cases, heterogeneous and multi-vendor storage systems are unified into a single pool. Application-usable volumes are carved from the pool, and administrators only need to focus on the SVS200 or XP array, rather than the individual systems comprising the pool.
Where to from Here
From this brief overview of Virtualisation, it is clear it will continue to be a major theme because it has so much to offer the data centers of Asia-Pacific companies. This is not only in terms of cost reductions, but once a company has Virtualisation in place, it begins to appreciate a range of agility benefits that it previously did not have. For example, the ability to grow and shrink VMs or move them are benefits that will be increasingly appreciated as the trend to Virtualisation continues.
Many industry experts are of the view that the industry is now in the third wave of Virtualisation. The first generation concerned single-server partitioning. The second generation provided a single point of management across multiple physical and virtual machines. The third wave could potentially lead to changes in everything from intruder detection to firewall applications, patch management, the provision of far more sophisticated testing developments.
Letting go of the Physical
Between the fifteen percent of operating systems deployed on virtual machines in 2005 and the 40 percent figure projected by IDC there is a sharp upward curve. If virtual machines reach this projected figure, Virtualisation will need to undergo significant pickup in the next two years.
If this eventuates, a key change in mindset will need to occur. For example, with VMWare Infrastructure 3.1 now supporting virtual machines of up to 16 GB of memory and breaking open the database and SQL servers, it will be exciting to leverage the opportunity that Virtualisation can offer.
For Virtualisation to have its maximum effect, to achieve the maximum efficiency, people will need to learn to let go of the physical. Once people learn how letting go can benefit their business, they will realize it is a good thing. When it occurs, it is at this point that Virtualisation will explode in the market.
Aman Dokania, Director, Infrastructure Software, Hewlett-Packard, Asia-Pacific.
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