Overview of Hyper-V Server Virtualization

There is no doubt that virtualization is one of the most popular IT technology fields today, whether it is a promotional campaign from a large number of IT technology vendors to launch virtualization products in the market, this can be seen from the large-scale use of virtualization solutions by enterprise users. So what is virtualization?

In fact, this problem can be understood from two aspects. First, from a narrow perspective, virtualization usually refers to applications of certain Virtual Machine technologies, such as Hyper-V and VMware ESX ), with this technology, we can run multiple operating systems on the same physical computer, which can effectively save the hardware investment, integrate applications, and reduce management costs. However, from a broad perspective, we can consider virtualization as a technical means to effectively isolate computing resources.

Therefore, it is not limited to virtual machine products. All technologies that can achieve this feature can be categorized into virtualization. This may not be very easy to understand, but it can be explained through a brief example: a user uses an application to complete his/her work, in fact, this scenario we are very familiar with involves many layers. First, the application you use is installed on a specific operating system, the operating system is installed on a specific hardware platform. User data is stored in a specific local disk of the computer, and the computer network is connected to a specific local physical switch ...... All these layers are closely related. You cannot easily separate one of them from other layers, for example, you can copy this application to another computer with different operating systems. It can run exactly the same way as before and access the original data. This is the static computing model shown in Figure 1. All layers are closely related.

 

If we can effectively separate these resource hierarchies, just like on the right side of Figure 1, changing or even replacing a certain level will not affect other levels, then we can regard this technology as a virtualization technology. The most common virtualization technology-virtual machines are the separation of the close binding between operating systems and hardware, this allows us to copy a virtual machine from one physical machine to another without making any changes to it. Of course, from this perspective, the remote desktop or terminal service is also a virtualization technology-display virtualization, because it achieves the separation of application presentation and applications, operating systems, and hardware devices, regardless of the geographical location, as long as the client of the terminal service can access the applications running on the server as locally. Therefore, in a broad sense, virtualization is not limited to virtual machine technology, but can be implemented at many levels, at the same time, many virtualization manufacturers have also launched corresponding Virtualization Technologies and products at all levels, for example, Microsoft's virtualization strategy includes many products and technologies such as server virtualization, presentation virtualization, storage virtualization, and application virtualization.

Virtualization has become a hot topic in enterprise IT applications. The main reason is that virtualization can effectively isolate resources and make full use of limited computer resources, reducing investment in cost and management, and isolating computing resources breaks the original tight binding between these resources, making it more flexible for enterprises, it has the dynamic characteristics of "changing as needed.

Windows Server 2008 R2 supports Virtualization in many aspects, including displaying virtualization through Terminal service roles) and network virtualization through VPN components) and server virtualization through the Hyper-V Role), while Hyper-V is a new component that provides a wide range of application prospects, because the need to run multiple operating systems on the same physical device is still the most important form of enterprise virtualization applications. Hyper-V is known as the server virtualization platform by Microsoft, and its main goal is to achieve the virtualization of the server operating system. Typical application scenarios of Hyper-V server virtualization include:

First, server integration. In fact, many servers in an enterprise are not as busy as we think. In general, the running load of many servers is very low. Maybe the CPU usage is usually less than 20%, and the utilization of other resources is also very low, however, considering operating system versions, application conflicts and compatibility, and ease of management, you can only install them on independent physical servers, it brings a lot of waste. Hyper-V enables us to run multiple different types of operating systems on the same physical hardware server. These operating systems are logically isolated, naturally, there will be no compatibility issues. In this way, the operating systems and applications running on several, dozens, or even dozens of physical servers can be integrated into one physical server, the cost saving is obvious, and at the same time, it also brings a great improvement in management efficiency.

The second is to help achieve business continuity. The so-called business continuity is how to ensure the maximum availability of application systems in the enterprise environment. In the past, this was a great challenge for IT management. For example, it is common to upgrade and replace the hardware of physical servers, however, these operations can only be performed after the server is shut down. This will make the applications on the server unavailable for a long time. For some key application systems, this is unacceptable. If Hyper-V is used to virtualize the application server, this problem can be well solved, because the operating system in the virtual machine is not bound with the hardware at the bottom of the server, therefore, it is easy to quickly migrate the running Virtual Server to another physical server to continue running, and upgrade and replace the hardware of the original server. Some application system high availability solutions are cumbersome to implement, and different application systems use completely different high availability Technologies, which also brings a lot of inconvenience to the high availability management of application systems. If Hyper-V is used to virtualize the application Server, Hyper-V can easily achieve high availability of virtual machines based on the Failover cluster of Windows Server 2008 R2, therefore, virtual machines and application systems running on Hyper-V naturally become highly available application systems, which makes building and managing highly available application systems very simple. In addition, virtualization greatly simplifies server backup and disaster recovery, and provides fast disaster recovery capabilities.

Again, it is to build a test and development environment. For software companies and IT solution providers, development and testing environments are obviously necessary, but as information technology continues to deepen in the enterprise, the development and testing environments of enterprise application solutions have become an essential part of the enterprise IT environment. However, the cost of building a test environment, the provision and management of the test environment, and the migration from the test environment to the production environment are all tricky issues. After using a server virtualization platform such as Hyper-V, we can build a testing and development environment at a lower cost, on the other hand, management of the test environment, transformation from the test environment to the production environment, and migration will become easy to implement.

Finally, it is to build a dynamic data center. Hyper-V can separate the virtual server operating system and the applications running above from the physical hardware, this gives great flexibility in application system management, control, high availability, migration, and disaster tolerance, therefore, Hyper-V can provide a core support platform for building dynamic enterprise data centers.

Microsoft also had a Server virtualization product before Windows Server 2008 R2 Hyper-V-Virtual Server 2005, however, we need to know that Hyper-V is different from Virtual Server2005 in terms of application, but they are not the same product, hyper-V is not the upgraded version of Virtual Server 2005. Hyper-V and Virtual Server 2005 have completely different architectures, although as users do not need to know much about Hyper-V principles and mechanisms, however, as shown in figure 2, at least one important point is that the "virtual machine guest)" and the so-called "host)" in Hyper-V both run at the same level, the virtual machine operating system is not running inside another operating system. That is to say, Hyper-V does not have the "real operating system" or "Virtual Operating System, you can think that they are both Virtual or true, which is one of the biggest differences between Hyper-V and Virtual Server structures.

 

One of the most direct advantages of this structure is that Virtual machines in Hyper-V can achieve better performance and scalability than traditional host-type Server virtualization products such as Virtual Server. At the same time, thanks to hardware-based virtualization support, virtual machines can be effectively isolated and protected, so as to provide higher security on this virtualization platform. All of this makes Hyper-V a more stable and reliable platform for enterprise-level virtual architecture.