1. LO3 – Understand Business IT Systems
3.2 – Virtualisation

2. Virtualisation is to create a simulated or virtual network, computer or server using software.
Server virtualisation is not new; it has been used in mainframes since 1970s.
Normally the operating system and hardware are closely linked so that only some applications can run simultaneously to prevent problems such as registry conflicts. To operate additional applications, additional physical servers need to be installed, possibly running only a single application. Server virtualisation enables a single physical server to run several
applications, each appearing to have its own server.
Storage virtualisation works in a similar way by separating the physical storage server from the logical storage server. It can take two forms:
Block-level, which allows a storage area network or SAN to use numerous storage arrays across the network as if they were a single array.
File-level, which allows network attached storage (NAS) and removes the link between the data items and their physical locations on a particular file server.
Cloud computing is not virtualisation. The cloud uses existing technology to deliver services, such as security, storage and data manipulation, to users over a network. It is used like a utility – you can increase the size or range of
your usage through payment.
Hybrid cloud computing is a mixture of private cloud, public cloud and locally owned services. As its activities and data requirements change, so the organisation can adjust its usage more effectively and efficiently.

3. Local Area Networks (LANs) are created using hardware (cables)
Local Area Networks (LANs) are created using hardware (cables). Virtual networks are created using software.

4. Advantages of Virtualization
The advantages of switching to a virtual environment are plentiful, saving you money and time while providing much greater business continuity and ability to recover from disaster.
Reduced spending. For companies with fewer than 1,000 employees, up to 40 percent of an IT budget is spent on hardware. Purchasing multiple servers is often a good chunk of this cost. Virtualizing requires fewer servers and extends the lifespan of existing hardware. This also means reduced energy costs.
Easier backup and disaster recovery. Disasters are swift and unexpected. In seconds, leaks, floods, power outages, cyber-attacks, theft and even snow storms can wipe out data essential to your business. Virtualization makes recovery much swifter and accurate, with less manpower and a fraction of the equipment – it’s all virtual.
Better business continuity. With an increasingly mobile workforce, having good business continuity is essential. Without it, files become inaccessible, work goes undone, processes are slowed and employees are less productive. Virtualization gives employees access to software, files and communications anywhere they are and can enable multiple people to access the same information for more continuity.
More efficient IT operations. Going to a virtual environment can make everyone’s job easier – especially the IT staff. Virtualization provides an easier route for technicians to install and maintain software, distribute updates and maintain a more secure network. They can do this with less downtime, fewer outages, quicker recovery and instant backup as compared to a non-virtual environment.
A virtual network is flexible. It is easy to add or remove computer for the VLAN using software. There is no need to add extra cables.
It is much easier to install software needed by specific groups of people e.g. if the finanace office need accounting software but the students do not, the network technician can install that software centrally just onto one specific network.
Network traffic can be limited to each virtual network, there is less overall traffic that if everyone were having to use the whole LAN. This means that data can be sent/received faster and network performance is improved )if a switch is used rather than a hub)
Improved security – if one VLAN is compromised for instance with a virus, because the others are partitioned they will not be affected.

5. Disadvantages of Virtualization
The disadvantages of virtualization are mostly those that would come with any technology transition. With careful planning and expert implementation, all of these drawbacks can be overcome.
Upfront costs. The investment in the virtualization software, and possibly additional hardware might be required to make the virtualization possible. This depends on your existing network. Many businesses have sufficient capacity to accommodate the virtualization without requiring a lot of cash. This obstacle can also be more readily navigated by working with a Managed IT Services provider, who can offset this cost with monthly leasing or purchase plans.
Software licensing considerations. This is becoming less of a problem as more software vendors adapt to the increased adoption of virtualization, but it is important to check with your vendors to clearly understand how they view software use in a virtualized environment to a
Possible learning curve. Implementing and managing a virtualized environment will require IT staff with expertise in virtualization. On the user side a typical virtual environment will operate similarly to the non-virtual environment. There are some applications that do not adapt well to the virtualized environment – this is something that your IT staff will need to be aware of and address prior to converting.