This article on the VPS used several common technology OpenVZ, Xen, KVM to do a simple introduction and comparison, in case you choose your own appropriate VPS
Many people see the same configuration of the VPS price difference is very large, it is not understood, in fact, there are many types of virtual VPS use, such as OpenVZ, Xen, KVM, Xen and HVM and PV. In +xen, PV is semi virtualized, HVM is full virtualization, PV can only be used for Linux kernel system, more efficient, HVM can be virtual all the common operating system (can use Windows), + theoretical efficiency is slightly lower than PV, in addition, HVM need CPU Virtualization command support, PV no such requirement. KVM is a new virtualization project that sells KVM-less VPS vendors, but it is said that KVM virtual technology + surgery is more robust. The OpenVZ is a linux-vserver-like operation system-level full virtualization solution, currently based on Xen and OpenVZ VPS services more +. This article on the VPS used several common technology OpenVZ, Xen, KVM to do a simple introduction and comparison, in case you choose your own appropriate VPS.
OpenVZ is an operating system-level virtualization technology that is a layer of application on the underlying operating system, meaning easy to understand and low weight overhead, which generally means better performance. But OPENVZ configuration is more flexible, to the black-hearted service providers to change the opportunity to lower restrictions.
Advantages: Now sold outside this type, the licensed memory is oversized, the CPU is strong, but also a lot of sellers, comparability is very strong. The price is very high.
Disadvantage: Oversold, no not oversold, resulting in a variety of stone plates, diamond plate. The associated CPU is also too fragmented to make performance appreciation less than 1/10 of its mark. Then there is memory, basically OPENVZ technology is not exclusive, are shared, others more you will be less, and this technology is the biggest disadvantage is the memory down directly when the machine. There are also a variety of inconvenient to open VPN.
Xen is a semi virtualization technology, it is not a real virtual machine, but it is equivalent to running a kernel of the instance, free to load the kernel module, virtual memory and Io, stable and predictable. Divided xen+pv+ and XEN+HVM, the difference is that PV only support Linux, and HVM support win system.
Advantages: Memory exclusive, although small but guaranteed to allocate. Part of the virtual technology determines that even oversold is not too outrageous. So the average hen even super, also rarely lead to stone plate. Of course the chicken has pt, except. The other is that even if the memory is low will not be lost, but will not respond for some time.
Disadvantage: Small memory, hard disk, small bandwidth (above 3 points and the same price OpenVZ comparison). Because there is no way to sell, the 3 basic configurations can only be lowered to make money. There is the supplier error is not aligned, and most of the time to say Xen Mi Youming is PV or HVM, in fact, PV performance is superior to HVM.
Advantages: Similar to Xen, a better thing than Xen is that the KVM is completely virtual, so regardless of the PV and HVM, all of the KVM class + virtual technology can be installed in various Linux distributions and a variety of win distributions, regardless of whether the supplier on the homepage to support win, As long as you have enough win to run, it will certainly be able to install + up, just the problem of methods.
Disadvantage: Precisely because the KVM can install any type of operating system, resulting in toss emperor even in the 128m machine installed win2003 (up + directly all the CPU and memory for hard disk IO, do not understand these people want to dry god horse). The result is that all the KVM neighbors have to look at the neighbors around you. So put, a node under as long as + 5, 6 Such toss Emperor, sorry, your hard drive is basically a stone plate.
The individual tends to be xen because it is an acceptable compromise for both the vendor and the customer. OpenVZ oversold too powerful, KVM, etc. see RP, these 2 kinds of not suitable for those who do not want to toss just want to do station webmaster.