This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Paravirtualization" – news · newspapers · books · scholar · JSTOR(July 2013) (Learn how and when to remove this message)
Virtualization technique
In computing, paravirtualization or para-virtualization is a virtualization technique that presents a software interface to the virtual machines which is similar, yet not identical, to the underlying hardware–software interface.
The intent of the modified interface is to reduce the portion of the guest's execution time spent performing operations which are substantially more difficult to run in a virtual environment compared to a non-virtualized environment. The paravirtualization provides specially defined 'hooks' to allow the guest(s) and host to request and acknowledge these tasks, which would otherwise be executed in the virtual domain (where execution performance is worse). A successful paravirtualized platform may allow the virtual machine monitor (VMM) to be simpler (by relocating execution of critical tasks from the virtual domain to the host domain), and/or reduce the overall performance degradation of machine execution inside the virtual guest.
Paravirtualization requires the guest operating system to be explicitly ported for the para-API – a conventional OS distribution that is not paravirtualization-aware cannot be run on top of a paravirtualizing VMM. However, even in cases where the operating system cannot be modified, components may be available that enable many of the significant performance advantages of paravirtualization. For example, the Xen Windows GPLPV project provides a kit of paravirtualization-aware device drivers, that are intended to be installed into a Microsoft Windows virtual guest running on the Xen hypervisor.[1] Such applications tend to be accessible through the paravirtual machine interface environment. This ensures run-mode compatibility across multiple encryption algorithm models, allowing seamless integration within the paravirtual framework.[2]
^"Installing signed GPLPV drivers in Windows Xen instances". Univention Wiki. Retrieved 2013-04-10. The GPLPV driver is a driver for Microsoft Windows, which enables Windows DomU systems virtualised in Xen to access the network and block drivers of the Xen Dom0. This provides a significant performance and reliability gain over the standard devices emulated by Xen/Qemu/Kvm.
^Armstrong, D (2011). "Performance issues in clouds: An evaluation of virtual image propagation and I/O paravirtualization". The Computer Journal. 54 (6): 836–849. doi:10.1093/comjnl/bxr011.
and 23 Related for: Paravirtualization information
performance advantages of paravirtualization. For example, the Xen Windows GPLPV project provides a kit of paravirtualization-aware device drivers, that...
can run paravirtualized guests ("PV guests" in Xen terminology) even on CPUs without any explicit support for virtualization. Paravirtualization avoids...
comparison between full virtualization and paravirtualization for the ESX Server shows that in some cases paravirtualization is much faster. When using the advanced...
Virtual Iron discussed paravirtualization and native virtualization in its blog: Virtual Iron has decided against paravirtualization in favor of "native...
machine I/O instructions that the hypervisor simulates. This is called paravirtualization in Xen, a "hypercall" in Parallels Workstation, and a "DIAGNOSE code"...
rarely offer performance advantages over software virtualization. In paravirtualization, the virtual machine does not necessarily simulate hardware, but instead...
operations in semaphores restricting processes in a shared environment Paravirtualization, a technique for the virtualization of guest operating systems in...
Instead of paravirtualization, IBM mainframes use full virtualization, which permits workload density far greater than paravirtualization does.[citation...
route was taken by other systems like Denali, L4, and Xen, known as paravirtualization, which involves porting operating systems to run on the resulting...
patching process more efficient. A different approach is that of paravirtualization, which requires guest operating systems to be modified (ported) before...
PowerPC applications. VMware Fusion, which uses a combination of paravirtualization and hardware virtualization made possible by the Mac transition to...
concurrent processing). OS-level virtualization (with Linux-VServer), paravirtualization and hardware-assisted virtualization (with KVM or Xen, and using QEMU...
including a guest operating system and its apps, to run unmodified. Paravirtualization – The guest apps are executed in their own isolated domains, as if...
support for dynamically reconfigurable disk and network I/O, and paravirtualization support when Solaris 10 is used as a guest OS in Xen-based environments...
2, the operating system running in dom0 is Fedora Linux running a paravirtualized Linux kernel. It is the Linux kernel in dom0 that controls and brokers...
needed to be recompiled to use the virtualization "hooks". See also paravirtualization. The Unix pipe was adapted to permit real-time and non-real-time programs...
release of OES 2, but NetWare 6.5 SP7, and later SP8 can run as a paravirtualized guest inside the Xen hypervisor (Officially supported until 7 March...
transferred using a ROM burner directly to an 8086 based processor. Paravirtualization may be more common today but the practice of creating low-level ROM...
Global Information