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This article focuses on "what are the mainstream virtual machine programs commonly used by VPS hosts?" interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Next let the editor to take you to learn "what are the mainstream virtual machine programs commonly used by VPS hosts?"

VPS (Virtual Private Server Virtual Private Server) technology, which divides a server into multiple virtual private servers. The technology to realize VPS is divided into container technology and virtualization technology. In containers or virtual machines, each VPS can assign independent public network IP addresses, independent operating systems, and achieve isolation of disk space, memory, CPU resources, processes and system configurations among different VPS, so as to simulate the experience of "exclusive" use of computing resources for users and applications. VPS can reinstall the operating system, install the program, and restart the server separately, just like a stand-alone server. VPS provides consumers with the freedom to manage configuration, which can be used for enterprise virtualization or for IDC resource leasing.

IDC resource lease, provided by VPS provider. Different VPS providers use different hardware and VPS software, and different sales strategies, the use of VPS experience is also quite different. In particular, when VPS providers are oversold, resulting in physical server overload, VPS performance will be greatly affected. Relatively speaking, container technology is more efficient and easier to oversell than virtual machine technology, so generally speaking, the price of container VPS is higher than that of virtual machine VPS.

These VPS hosts share hardware, software licenses, and management resources for maximum efficiency. Each VPS host can assign independent public network IP address, independent operating system, independent super-large space, independent memory, independent CPU resources, independent execution programs and independent system configuration, etc. VPS host users can not only assign multiple virtual hosts and unlimited enterprise mailboxes, but also have independent host functions, and can install their own programs and restart the host separately.

Let's talk about some common VPS virtual machine programs:

1. Xen

Official website: http://xen.org/

Xen, developed by the University of Cambridge, is based on a complete division of hardware. Physically, you can only allocate as many resources as you have, so it is difficult to oversell. It can be divided into Xen-PV (paravirtualization) and Xen-HVM (full virtualization).

Xen cannot oversell memory and hard disk. When the parent server has only 16g of memory and 100g of hard disk, it will directly occupy 1G of server memory and 25g of hard disk when turning on the 1G memory of Xen architecture (any virtualization) and the submachine of 25g hard disk, so the performance of Xen is better than that of OpenVZ when it is oversold.

Xen-PV: paravirtualized, so it is only suitable for linux series VPS, but its performance loss is relatively small, about 4% of the parent machine.

Xen-HVM: fully virtualized, you can install windows or freely mount ISO files to install any system. Because it is fully virtualized, the performance loss is large, which is about 8% and 20% relative to the performance of the parent machine.

People suitable for Xen: customers who have a sufficient budget and want VPS to have high performance.

Xen Note: note the difference between Xen-PV and Xen-HVM.

Xen available system: Xen-PV: pure Linux,Xen-HVM: support Windows, Linux and so on.

Xen represents the merchant: Linode.com

II. OpenVZ

Official website: http://openvz.org/

OpenVZ (abbreviated as OVZ) adopts the kernel of SWsoft's Virutozzo virtualization server software product and is an operating system-level server virtualization architecture based on Linux platform. This architecture directly calls the kernel in the parent server (parent machine) to simulate the generation of the child server (VPS, small machine), so it has only 1-3% performance loss compared to the parent server after virtualization.

Of course, OpenVZ can be oversold, meaning that a server has a total of 16 gigabytes of memory, and he can open a sub-server configured with 1 gigabyte of memory by more than 17. Because his virtual architecture relationship belongs to: how many customers use, deduct the number of parent servers, so the VPS of OpenVZ architecture is cheaper. However, due to the oversold factor, if the service provider is endlessly oversold, it will lead to a sharp decline in the performance of the server.

Another feature of OpenVZ is that it directly calls the kernel of the parent server, so it can cause some software to be unavailable and some kernel files to be unmodifiable.

OpenVZ applicable crowd: novice, low-budget customers

OpenVZ Note: resources are not unique to you, so you need to pay attention to testing virtual network card support when installing VPN service.

OpenVZ available system: Linux (Windows is not supported)

OpenVZ represents the merchant: Buyvm.net

III. KVM

Website: http://www.linux-kvm.org/

KVM is a full-featured virtualization architecture under Linux. VPS based on KVM architecture has no system by default. You can upload ISO or call the ISO provided by the service provider to install the system manually. This is very suitable for customers who love DIY's own VPS.

Because KVM architecture has full-function virtualization architecture, and even has independent BIOS control, it has a great impact on the performance of the parent server, so VPS based on KVM is more expensive, but KVM VPS is freer than VPS of other architectures.

KVM is suitable for people: the Emperor of Teng Teng.

KVM Note: virtualization performance is slightly lower than Xen

KVM available systems: Windows, Linux series

KVM represents the merchant: Hostgation.com

IV. Hyper-V

Website: http://www.microsoft.com/zh-cn/server-cloud/

Hyper-V is a virtualization product of Microsoft. Most domestic VPS service providers use this architecture, mainly because it is customized by Windows and is more convenient to manage. The current Hyper-V also supports Linux, but the performance loss is relatively serious.

Hyper-V perfectly supports Windows systems, including 32-bit and 64-bit. If you choose VPS with Hyper-V architecture, it is strongly recommended to use Windows.

Hyper-V cannot oversell memory at present, but it can oversell hard drives, which are deducted according to customer usage. Generally speaking, the hard drive of the server will not be 100% used up, don't worry about this.

People suitable for Hyper-V: Windows system enthusiasts

Hyper-V Note: low performance of Linux operating system

Hyper-V available systems: Windows, Linux

5. VMWare

Website: http://www.vmware.com/

VMWare is a fully functional and fully virtualized software developed by the global leader in desktop-to-data center virtualization solutions. However, because it is very expensive for VMWare to set up a series of products similar to VPS (including independent panels), most of them use VMWare services to provide VPS using VMware workstations (VMware Workstation).

Using VMware workstation (VMware Workstation) to set up VPS is without control panel, and the operating system needs to be installed manually by service providers, but now it is very easy to find KEY, the god of VMware Workstation, on the Internet, which saves a lot of costs for VPS service providers. It is generally used for new start-up VPS service providers.

VPS with VMWare Workstation can be oversold because, like the OpenVZ architecture, the memory used by the sub-machine is deducted from the system memory, but insufficient physical memory may cause the parent server to use Windows virtual memory.

People suitable for VMWare: customers who build stations or hang up seriously.

VMWare Note: no control panel

VMWare available systems: Windows, Linux series

The above measurement of oversold refers to memory, disk, other hardware conditions, such as network bandwidth, CPU and so on are not considered.

The difference between PS:Xen and OpenVZ

Xen is composed of dom0 and domU. Dom0 is a virtual CPU, IO general route and other resources for different kernel working on DomU to run.

The advantage of this is

1. There are fewer restrictions on the operating systems that can be run.

2. The crash of the system on domU will not affect other dom. Of course, there will still be problems when Dom0 breaks down.

Disadvantages:

1. Due to the need for physical resources such as virtual CPU,BUS, the overhead will be a little more.

OpenVZ uses a completely different approach, creating virtual machines that use and work under the same kernel.

The advantage of this is

1. The performance is good.

Disadvantages:

1. Any kernel bug will endanger all virtual machines. The possibility of crash by kernel bug is greatly increased.

two。 He needs to make a lot of changes to the kernel.

The most obvious distinction is that XEN VPS has swap region, OpenVZ VPS based on RHEL5 has no swap region, and OpenVZ VPS based on RHEL6 has VSwap region.

At this point, I believe you have a deeper understanding of "what are the mainstream virtual machine programs commonly used by VPS hosts?" you might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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