I. Background of Virtualisation
Server / hardware virtualisation allows a single physical machine to run multiple virtual machines on top of a host operating system or a virtualisation layer. The resources of the single computer are shared across the virtual machines. Each virtual machine emulates a physical computer and has its own CPU, memory, disks and network interface card. In other word, a single physical machine is able to install multiple different OS such as Window, Linux and Unix.
One of the most common approaches to server virtualisation is to use hypervisor technology. Hypervisors use a thin layer of code in software to achieve fine-grained, dynamic resource sharing. Hypervisor can be further classified into Type 1 and Type 2. Type 1 hypervisors run directly on the system hardware which are typically the preferred approach for server consolidation because they can achieve higher virtualisation efficiency whereas Type 2 hypervisors run on a host operating system that provides virtualisation services such as I/O device support and memory management. Virtualisation solutions that use a Type 2 hypervisor are also referred to as operating system (OS) virtualisation, and in some environments are called containers.
2. Desktop Virtualisation
Desktop virtualisation is also known as presentation virtualisation. To run multiple applications, instead of running the applications and displaying the interfaces on the same machine, another option is desktop virtualisation. It enables a client machine to run applications and display interfaces on other corresponding servers through remote desktop.
The major advantage of desktop virtualisation is that the management of data and program of each application can be centralised. This saves the installation of the applications on each client machine, and improves efficiency as it decreases the communication overhead between the client and the server.
3. Application Virtualisation
Apart from the virtualisation of hardware and application interface, the application itself can also be virtualised. Applications may be incompatible to each other when they are run on the same operating system, for instance because of the sharing of specific Dynamic Link Libraries (DLLs) or registry entries.
Application virtualisation is a way to solve the problem. It includes the shared resource and the actual application in a virtual application. Resource causing incompatibility is duplicated in each virtual application. Hence, incompatible applications are possible to be run on the same operating system.
4. Virtual Infrastructure - Cloud Computing
While virtualising a single physical computer by hardware virtualisation is already popular, building a Virtual Infrastructure is another way to implement hardware virtualisation.
Servers, storage devices, network bandwidth on the entire infrastructure can be combined into a pool of resources to be dynamically allocated. Virtual machines can be shared over the entire infrastructure, hosting various operating systems and applications.
Implement virtualization in UNIX environment
A full refresh of the server environment was completed using 12 x IBM UNIX servers using logical & virtual partitioning which allows the department to run multiple independent servers on a single physical server.
See the article: http://www.origina.ie/site-map/about-origina/41/93
Key Benefits Achieved through Virtualisation
- Increase efficiency of the existing resources - Pooling common infrastructure resources and breaking the legacy "one application to one server" model with server consolidation can increase the efficiency and utilisation of the computing resources.
- Reduce data centre costs - Fewer servers and related IT hardware under virtual environment means reduced real estate and reduced power and cooling requirements. In addition, virtualisation technology lets you improve your server to admin ratio, and hence personnel requirements are reduced as well.
- Increase availability for improved business continuity - Under virtualisation, the organisation can securely backup and migrate entire IT virtual environments with no service interruption. This can eliminate or reduce the needs for planned downtime and enable the service to be recovered immediately from unplanned issues.
- Gain operational flexibility - With appropriate hardware configuration, virtualisation able to provide faster server, improve the speed of desktop and application deployment as well as provide dynamic resource management.
- Improve desktop manageability and security - Deploy, manage and monitor secure desktop environments that users can access locally or remotely, with or without a network connection, on almost any standard desktop, laptop or tablet PC.
ITS Virtualization Service
Virtualization as a Service (VaaS) is deployed for departments at the University of Michigan. VaaS offers low cost virtual servers using enterprise class hardware in secured datacenters. Using VaaS virtual servers can yield significant cost savings with numerous benefits and features.
See the article: http://vaas.umich.edu/benefits.aspx
Harness the Full Potential of High-Performance IT Hardware
Most x86 computers today operate at a mere 10-15% of their total computing capacity, leaving vast IT resources untapped and unusable. But with virtualisation, you can increase utilisation to as much as 85% by running multiple operating systems on a single computer..