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Questions tagged [xen]

Xen is a virtualization technology for IA-32, x86-64 and ARM architectures.

Xen is an Open Source "type-1" hypervisor that provides high-performance virtualization of IA-32, x86-64 and ARM architectures.

The homepage for the project is: http://www.xenproject.org/

One of the Xen project goals is to take advantage of new developments in system architectures to demonstrate their advantages and serve as the reference hypervisor of choice.

Development activity takes place on the xen-devel@xen.org public mailing list, and questions from users about deploying Xen are served by the xen-users@xen.org public mailing list.

Xen originated from the Cambridge University Computer Laboratory and was first described in the research paper "Xen and the Art of Virtualization" at SOSP in 2003. This introduced "paravirtualization" as the concept of modifying the kernel of the guest operating system to be aware of the hypervisor, and so change its behaviour to optimize performance, whilst still allowing guest applications to run unmodified.

Just as Linux distributions provide an environment and packaged version of the Linux kernel, similarly Xen is packaged and made available commerically by multiple vendors, including Citrix, Oracle, SuSE (or their current owner), and RedHat.

Documentation

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What are the differences between QEMU and VirtualBox?

Recently, I found out that there is the QEMU project. I've used VirtualBox before, and I know about Xen and VMWare. What are the differences between QEMU and VirtualBox? Should I stick with VirtualBox? In which cases is QEMU better?
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Detect virtualized OS from an application?

I need to detect whether my application is running within a virtualized OS instance or not. I've found an article with some useful information on the topic. The same article appears in multiple places, I'm unsure of the original source. VMware…
DGentry
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What's the differences between Xen, QEMU and KVM?

I know QEMU is used by Xen, and KVM is a fork of QEMU. So, KVM includes that Xen adds to QEMU ? What is the name ? Thanks
Xorax
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CUDA / OpenCL within a Virtual Machine / Hypervisor

Anyone know of any virtualisation solutions that either allow CUDA/OpenCL access directly or implement CUDA/OpenCL abstraction. UPDATE: Thank you those who commented. While classical 'desktop' virtualization would be nice, I suspect the likes of…
Bolster
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AWS::CloudFormation::Init how does it work?

We can use AWS::CloudFormation::Init to execute commands and upload files after starting an instance. But does anybody know what are the internals of this operation (from Amazon's side)? When we pass a template in, at what point are the files or…
SoYoung
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Docker Container compared with Unikernel

I recently deployed a tiny Haskell app with docker, using "scratch-haskell" as a base image. Then I read about Unikernels and HALVM. And I got a little confused. My docker container is about 6MB large. A Unikernel (with the same haskell app) would…
Robin
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Is there an OS command I can run to determine if running inside a Xen based virtual machine

Is there an OS command I can run from within a Xen based virtual machine to tell me that it is a virtual box rather than a physical box - I heard that the kernel had some self awareness smarts about it. e.g. like an extra column in "ps" output or…
pjp
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Java VMs that do not require an operating system?

I know that BEA was working on LiquidVM which didn't require an underlying operating system, but would like to know if anyone in the open source community is working on something similar. Ideally I would like to find an implementation where the VM…
McGovernTheory
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What are "non-virtualizable" instructions in x86 architecture?

Before the advent of hardware assisted virtualization there were instructions that could not be virtualized due to various reasons. Can somebody please explain what those instructions are and why they cannot be virtualized?
Yadgar Woderf
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How to benchmark virtual machines

I am trying to perform a fair comparison of XenServer vs ESX and one comparison I would like to make is performance with multiple VMs. Does anyone know how to go about benchmarking VM performance in a fair way? On each server I would like to run a…
JamieH
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Which Linux distribution should I use as a Xen host?

I ordered a server for the home office and I would like to partition it with Xen. I think this will keep things clean and easier to maintain. I will be running things like MySQL, PostgreSQL, Tomcat, and my own code. What freely available Linux…
Stefan Arentz
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On Linux SCHED_FIFO and SCHED_RR

I'm writing a a very small daemon that must remain responsive even when a system is under severe stress. I'm looking at the differences between SCHED_FIFO and SCHED_RR in regards to scheduling, as well as trying to determine a sensible…
Tim Post
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How to shutdown or reboot VM forcely in XEN?

It happen to me to find a VM in XEN run out of memory, OS kill its shell tty so there is no way to input command in VM internally. The only way to fix is shutdown or reboot the VM. "xm shutdown VM-name" and "xm reboot VM-name" have been tried, but…
XuZhangning
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Generating function calls on data accesses in VMware ESXi

I am currently using a Simics module (see chapter 6) to listen for instruction fetches and data accesses, and run callbacks on all of those events so as to instrument a kernel that is running on Simics x86. For example, I can create a Simics module…
DIMMSum
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How is Docker related to exokernal approach like Mirage OS?

How is Docker related to exokernal approaches like MirageOS? For some information about MirageOS…
user570599
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