KVM is a full virtualization solution for linux on x86 hardware containing virtulization extensions (intel VT or AMD-V ) Full virtualization uses the processor based virtulization extensions On september 4,2008 Qumranet was acquired by Redhat Inc KVM ( kernel based virtual machine ) was developed by Qumranet, Inc. Normal linux kernel has the facility of virtulization in it by KVM NOte:QEMU code is used by KVM and XEN and also used by virtual Box QEMU has the ability to emulate multiple processors and multiple architecture QEMU itself runs on several host operating systems QEMU is a machine emulator: it can run an unmodified target operating system (such as Windows or Linux ) and all its application in a virtual machine. Specifically, the QEMU virtual CPU core library is released under the GNU Lesser General Public License (GNU GPL) Qemu was written by Fabrice Bellard and is free Software QEMU was presented in USENIX 2005 Annual Technical Conference. Full virtualization came up with intel-VT and Amd-V in 2005 That will, however have a nagative effect on the performance Note2: Xen allows/supports committing more CPUs to VMs (in total) than the total physical CPUs you have on the physical host.
Note1: Xen does not support committing more RAM to Vm's(in total) than the total physical RAM you have on the physical host.
Full virtualization uses the processors extensions Xen's full-virtualization additionally requires availability of Intel VT-x or AMD-V technology within the processor 32-bit x86 with PAE support ( physical Address Extensions ) Note: Xen support para-virtualization and also supports full virtualization it would know it is running on vitualized machine Lot of overhead is reduced on the physical host, the machine ran pretty fast Xen originated as a research project(XenoServer) at the university of Cambridge, In 2003 xen came out as a research project Emulated all the h/w virtually to fool the virtual PC. VMware was founded in 1998 and delivered its first product, VMware workstation, in 1999 Note: Virualization was not the whole idea behind creation of IBM system/360 It included features to facilitate time-sharing applications, notably virtual memory hardware and 32 bit addressing.
The IBM system/360 Model 67(s/360-67) was a mainframe, and first shipped in july 1996. You don't require anything else other than your Pc Virtualization/emulation software, creates virtual network The mechanism to run multiple instances/copies of various operating systems inside a base operating system, mainly to utilize under-used resources on the physical host, where base operating system is running. Like running multiple pc inside one physical set of hardware Virtualization : It is a method to create a virtual machine inside already existing machine # Brief Introduction about Virtualization Concepts #