This post is about the currently available virtualization technologies in the market. We've got XEN, KVM, VMware and Microsoft hyper-v virtualization technologies.
The former two are free and open source, while VMWare and hyper-v are paid-for versions. In our products, we mainly use XEN and KVM virtualization technologies. In the FusionCloud version evolution plan (),
XEN will have gradually phased out and all will later be converted to KVM. Therefore, after the FusionCloud 6.3.1 version, all products will be using KVM technology and the stock XEN will gradually delist. So why do we prefer KVM instead of XEN?
Now let's briefly introduce these two virtualization technologies.
XEN virtualization technology, also known as paravirtualization, is a virtual machine monitor developed by the University of Cambridge.
The XEN technology framework is shown in the following figure. It can be divided into three layers: the physical layer, the XEN hypervisor layer,
and the domain. The physical layer is the underlying hardware, such as the server; the XEN hypervisor is responsible for virtualizing the underlying hardware resources for use by the upper layer.
The XEN technology sets a privileged domain, the so-called domain0, which is a privileged virtual machine to assist management.
Manage other domains (domain u), so the server itself needs to allocate certain resources to domain0, which will reduce the resources that can actually be used to publish virtual machines, resulting in reduced resource utilization.
KVM (kernel-based virtual machine) is also called full virtualization or hardware-assisted virtualization.
KVM is a virtualization module embedded in the Linux operating system. It can convert the Linux standard kernel to VMM, so it is faster and does not need to manage the space domain0. It can use more resources for actual business processing,
but because of KVM. Embedded in the Linux kernel, the host operating system must be a Linux kernel.
From the current situation, redhat has given up XEN technology, and our company has gradually turned to KVM.
Alibaba Cloud used XEN in the early stage, and it is understood that it has recently turned to KVM.
Because of the need to pay for the use of VMware, there are fewer vendors, and hyper-v is only used by its own public Cloud Windows Azure.
Therefore, I personally think that KVM will gradually become a de facto standard for virtualization.
