Advantages and Disadvantages of Virtualization

Advantages of Virtualisation

Ø Benefits for Companies

ü Virtualization provides several benefits for companies, including:

ü Greater efficiency and company agility

ü Ability to more-effectively manage resources

ü Increased productivity, as employees access the company network from any location

ü Data stored on one centralized server results in a decrease in risk of lost or stolen data

Ø Benefits for Data Centers

ü Not only is it beneficial for companies, but virtualization provides several benefits for data centers as well, including:

ü Cutting waste and costs associated with maintaining and cooling its servers by maximizing the capabilities of one server

ü Allows data centers to be smaller in size, resulting in overall savings due to a reduction in —

ü Energy needed

ü Hardware used

ü Time and money needed for maintenance

Ø Reduced IT costs:

ü Capital expenditure savings. Virtualization lets companies reduce their IT costs by requiring fewer hardware servers and related resources to achieve the same level of computing performance, availability and scalability.

ü Operational expenditure savings. Once their servers are virtualized, IT staffs can greatly reduce the ongoing administration and management of manual, time-consuming processes by automating operations, thus resulting in lower operational expenses.

ü Data-center and energy-efficiency savings. As companies reduce the size of their hardware and server footprint due to the use of virtualization, they lower their energy consumption, cooling power and data-center square footage, thus resulting in lower costs.

Ø Easier backup and disaster recovery. Simple data recovery is another great advantage of this technology. For instance if your virtual server suddenly becomes corrupted you simply delete it and restore it from its virtual backup. You do not need to spend time and effort on restoring your entire system from scratch and then restore it from the latest backup. So a corrupted virtual system can be recovered in mere minutes.

Ø 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.

Ø 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.

Ø Improved System Reliability and Security. Virtualization of systems helps prevent system crashes due to memory corruption caused by software like device drivers. VT-d for Directed I/O Architecture provides methods to better control system devices by defining the architecture for DMA and interrupt remapping to ensure improved isolation of I/O resources for greater reliability, security, and availability.

Ø VMs are portable. Its just a huge file. Take that file with you anywhere and you have your files and operating with u whereever you go. However you can only run it on a pc that has a Virtualisation software, software that allows you to run virtual machines.

Ø Testing and learning. If your a software developer, you can test software inside a VM. If the VM would or ever crash your operating system due to your software, then the main operating system is not affected, only the VM would be.

Ø So its good for testing purposes. Its also good for testing a virtual network. You could set up multiple VMs and network each VM together as if they were separate machines. This would allow you to test out networking protocols.

Ø 3. If you have a server with lots of computing resources then you could create lots of webservers which are separate to each other and resell what they call 'virtual server' to customers. This means they get a slice of your computer resources. If their webserver shuts down abnormally, the machine wouldnt be affected as you they will only have access to their virtual machine.

Disadvantages of Virtualization

Ø 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.

Ø 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.

Ø 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.

Ø Not Supported by All Applications: If your CPU does not allow for hardware virtualization then you can run some operating systems in software virtualization but generally its slower. So slow that it would annoy you.

Some operating systems will not run in software virtualization and require that you have a CPU with hardware virtualization. So it would cost you more if you dont have a CPU with hardware virtualization.

When I paste text into word from a website, there appears to be a color background to the text that I cannot remove.How to solve this issue?

In Word 2010, click on File, Options, Advanced, under Cut, Copy, Paste and click on the drop down option for 'Pasting from other programs' and select 'Keep Text Only'.

In Word 2007, click on the Office button, Word Options, Advanced, under Cut, Copy, Paste and click on the drop down option for 'Pasting from other programs' and select 'Keep Text Only'.

Virtualization

Virtualization

Virtualization is defined as the abstraction of objects ("things"), creating a virtual (rather than actual) version of objects, such as an operating system, a server, a storage device or network resources.
 

For example, when you partition a hard drive into two partitions - C and D, say - you create virtual drives but the physical hard drive has not changed.

Operating system virtualization is the use of software to allow a piece of hardware to run multiple operating system images at the same time. The technology got its start on mainframes decades ago, allowing administrators to avoid wasting expensive processing power.

Similarly, Network attached storage (NAS) presents users with an abstract storage space - a single point of access to data - though in reality NAS contains many drives and tapes hidden from the end user.

In server virtualization, a software layer is inserted either directly on the physical server (host) hardware or on the host operating system. This software (also known as hypervisor or virtual machine monitor) allocates hardware resources (CPU, RAM, storage and networking) and allows a single server to run multiple operating system images at the same time. Each one of these operating systems is a `virtual server'.

Virtual machines are completely compatible with all standard x86 operating systems, applications and device drivers.

In other words, virtualization is a framework or methodology of dividing the resources of a computer into multiple execution environments, by applying one or more concepts or technologies such as hardware and software partitioning, time-sharing, partial or complete machine simulation, emulation, quality of service, and many others.

Note:==> The term "virtualization" is not always used to imply partitioning - breaking something down into multiple entities. Here is an example of its different (intuitively opposite) connotation: you can take N disks, and make them appear as one (logical) disk through a virtualization layer.

Virtualization allows higher utilization of servers, which usually run at a fraction of their capacity. By replacing physical servers with virtual ones, and consolidating many together, it is possible to reduce datacenter space, energy consumption, hardware costs and maintenance personnel. It is also easier to move virtual servers between hosts to form high availability, fault tolerant or other virtual clusters, thus improving business continuity, performance and responsiveness.

·         Without VMs: A single OS owns all hardware resources

·         With VMs: Multiple OSes, each running its own virtual machine, share hardware resources

·         Virtualization enables multiple operating systems to run on the same physical platform

Need for Virtualization/Why Virtualization: A List of Reasons

Virtualization can help you shift your IT focus from managing boxes to improving the services you provide to the organization. If you are managing multiple servers and desktops, virtualization can help you to:

Save money: Companies often run just one application per server because they don’t want to risk the possibility that one application will crash and bring down another on the same machine. Estimates indicate that most x86 servers are running at an average of only 10 to 15 percent of total capacity. With virtualization, you can turn a single purpose server into a multi-tasking one, and turn multiple servers into a computing pool that can adapt more flexibly to changing workloads.

Save energy: Businesses spend a lot of money powering unused server capacity. Virtualization reduces the number of physical servers, reducing the energy required to power and cool them.

Save time: With fewer servers, you can spend less time on the manual tasks required for server maintenance. On the flip side, pooling many storage devices into a single virtual storage device, you can perform tasks such as backup, archiving and recovery more easily and more quickly. It’s also much faster to deploy a virtual machine than it is to deploy a new physical server.

Reduce desktop management headaches: Managing, securing and upgrading desktops and notebooks can be a hassle. Desktop virtualization solutions let you manage user desktops centrally, making it easier to keep desktops updated and secure.

Resource optimization: Today's enterprise level computer resources are so powerful that they often have excess capacity. By virtualizing the hardware and allocating parts of it based on the real needs of users and applications, the available computing power, storage space and network bandwidth can be used much more effectively. Computers no longer need to be idle or performing below their capabilities because there are fewer connected users, or because the hosted application happens to be less demanding than the server can handle.

Virtual machines offer software developers isolated, constrained, test environments. Rather than purchasing dedicated physical hardware, virtual machines can be created on the existing hardware. Because each virtual machine is independent and isolated from all the other servers, programmers can run software without having to worry about affecting other applications, or external components affecting the execution of their code.

Consolidation: It is common practice to dedicate individual computers to a single application. If several applications only use a small amount of processing power, the administrator can consolidate several computers into one server running multiple virtual environments. For organizations that own hundreds or thousands of servers, consolidation can dramatically reduce the need for floor space, HVAC, A/C power, and co-location resources. This means the cost of ownership is reduced significantly, since less physical servers and floor and rack space are required, which in turn leads to less heat and power consumption, and ultimately a smaller carbon footprint.

Maximizing Uptime: Agility is all about being able to respond to changing requirements as quickly and flexibly as possible. Virtualization brings new opportunities to data center administration, allowing users to enjoy:

Ø Guaranteed uptime of servers and applications; speedy disaster recovery if large scale failures do occur.

Ø Instant deployment of new virtual machines or even aggregated pools of virtual machines via template images.

Ø Elasticity, that is, resource provisioning when and where required instead of keeping the entire data center in an always-on state.

Ø Reconfiguration of running computing environments without impacting the users.

Automatically Protect Applications from Server Failure: Server virtualization provides a way to implement redundancy without purchasing additional hardware. Redundancy, in the sense of running the same application on multiple servers, is a safety measure: if for any reason a server fails, another server running the same application takes over, thereby minimizing the interruption in service. This kind of redundancy works in two ways when applied to virtual machines:

Ø If one virtual system fails, another virtual system takes over.

Ø By running the redundant virtual machines on separate physical hardware you can also provide better protection against physical hardware failure.

Easily Migrate Workloads as Needs Change: Migration refers to moving a server environment from one place to another. With most virtualization solutions it is possible to move a virtual machine from one physical machine in the environment to another. With physical servers this was originally possible only if both physical machines ran on the same hardware, operating system and processor. In the virtual world, a server can be migrated between physical hosts with entirely different hardware configurations. Migration is typically used to improve reliability and availability: in case of hardware failure the guest system can be moved to a healthy server with limited downtime, if any. It is also useful if a virtual machine needs to scale beyond the physical capabilities of the current host and must be relocated to physical hardware with better performance.

Protect Investment in Existing, Legacy Systems: Server hardware will eventually become obsolete, and switching from one system to another can be difficult. In order to continue offering the services provided by these legacy systems, you can run it as a virtual machine on new, modern hardware, while the legacy system itself still behaves as if it were running on the same legacy hardware. From an application perspective, nothing has changed. In fact, its performance may well benefit from the newer underlying hardware. This gives the organization the time to transition to new processes without worrying about hardware issues, particularly in situations where the manufacturer of the legacy hardware no longer exists or cannot fix broken equipment.