To comprehend desktop virtualization technology, we must first comprehend the desktop virtualization development process. We can easily categorize desktop virtualization technology into three stages.
Before we knew what desktop virtualization meant, predecessors to this technology emerged from various fields and matured until they became the current desktop virtualization technology. This included two major technologies.
Almost everyone in the IT industry has used remote desktop technology. The RDP (Remote Desktop Protocol) protocol is used by Windows XP’s remote desktop, which allows users to log in, access, and use the target desktop from other computers. Microsoft first used the RDP protocol as an access protocol for Terminal Service on Windows Server, enabling multi-user mode and allowing users to use various applications on the server remotely without installing any applications locally.
To achieve interaction, this technology transfers the interface running on the target machine to the user’s actual operating machine screen and transfers a series of peripheral inputs, such as keyboard and mouse, to the target machine. The distinction between Terminal Services and Remote Desktop is that the former only manages the application, whereas the latter manages the entire desktop.
Desktop operation system virtualization
This topic distinguishes server virtualization technology with a focus on desktop operating systems that are virtualized. In fact, this concept is similar to the Vmware Workstation and Microsoft VPC methods for achieving a desktop-level operating system. Of course, this application model is frequently used by major developers and testers, even though the virtualization is not always a desktop system such as XP, 2000 Professional, Vista, and so on.
The reason for mentioning this here is that when virtualization technology was first introduced, some vendors defined it as desktop virtualization technology. For example, before the introduction of MED-v technology, Microsoft defined VPC as Microsoft’s desktop virtualization product.
The first generation of desktop virtualization technology
The first generation of desktop virtualization technology truly combines the remote access capability of remote desktops with virtual operating systems, allowing desktop virtualization to be used for enterprise applications as well.
First, to the current 4-core dual CPU processor 16G memory server, the maturity of server virtualization technology, as well as the enhancement of server computing power, so that the server can provide multiple desktop operating system computing power. For example, if the user’s XP system allocates 512M memory, and on average, a server can support 20-30 desktops running, it can be seen that if the desktop Centralized use of virtual desktop to provide, then 20-30 desktop procurement costs will be higher than the cost of the server, and management costs, security factors, have not been calculated, so the emergence of server virtualization technology, making desktop virtualization technology for large-scale enterprise applications.
Citrix, Microsoft, Vmware, and other vendors currently provide desktop virtualization solutions, and the remote access protocols used primarily utilize two protocols: the RDP protocol developed earlier by Citrix and later purchased by Microsoft and integrated into Windows, which is used by Microsoft and some of its desktop virtualization products; and the SSH protocol developed earlier by Citrix and later purchased by Microsoft and integrated into Windows. Secondly, the currently unique ICA protocol developed by Citrix itself, which Citrix uses in its application virtualization products and desktop virtualization products.
The second generation of desktop virtualization technology
The first generation technology realized the combination of remote operation and virtualization technology, and the lower cost enabled the popularity of virtual desktop technology, but it is not only the procurement cost that affects the popularity, but also the management cost and efficiency. To improve manageability, the II generation desktop virtualization technology further splits the desktop system running environment and installation environment, as well as the application and desktop split and configuration file split, greatly reducing management complexity and cost and improving management efficiency.
Desktop virtualization should be implemented after the completion of the corresponding security optimizations, which should include: access control, audit and logging, transmission channel encryption, storage encryption and protection, and so on. Among them is the protection of virtual storage. The most important aspect is the protection of the virtual desktop server; if the virtual desktop server is damaged, the entire virtual architecture is broken. A variety of methods can be used to protect virtual machine.