View Full Version : Virtual Machines, Xen, and more

28th February 2009, 08:29 PM
Hello all,

I have a few questions regarding VMs, Xen, and performance in general.

First, can anyone post a few good resources to learn the basics of virtual computing? I am pretty new to it and would love to learn all that I can.

Second, I recently gave the boot to Windows and installed Fedora 10. Under Windows, I was using VirtualBox for all of my virtualized computing needs. I had set up a virtual network with two virtual machines - one running Windows Server 2K3 and the other running Windows 2000 Pro. I could run both VMs at the same time and still use the host OS. Now I am trying a similar setup under Fedora, I am using VirtualBox to run Server 2K3 and Windows XP. The problem I encounter is that when I run one VM, one of my CPU cores rockets to 100% usage and the other hovers around 40% - 60% usage. Is there a way to enhance performance so I can run both VMs at the same time?

Third, what would be the effects of me installing the Xen runtime environment package or the Xen emulator for KVM?

Thanks to all for your replies!

System specs:
OS: Fedora 10 x86-64
CPU: Athlon 64 X2 3800+ (Toledo)
RAM: 2GB PC3200
GPU: GeForce 7600 GT XXX

28th February 2009, 09:17 PM
I enjoy using SUN xVM virtual box here runnining fed 7 on xVM on UBUNTU 8.10
Real Fun.
Sam of Jaffa

28th February 2009, 09:36 PM
Since you are running Fedora 10, I would recommend going with KVM as it is part of the distribution and the direction that Red Hat is moving in its virtualization tools. Over the next 3-18 months, there is going to be a lot of new stuff coming from Red Hat to support their virtualization roadmap (link (http://www.redhat.com/virtualization-strategy/?intcmp=70160000000HizEAAS))

At work, I maintain three 8-node clusters running Xen and the performance of KVM is about equal to that of Xen now. I played with VirtualBox and VMWare a couple of years ago, but decided to stick with the technology in the OS as it is easier to maintain and works very well. You do have to have a processor that supports either Intel VT or AMD vmx technology though to get the full benefits of either Xen or KVM. Another point is that Xen does not work with Fedora 10, KVM and qemu do.

There are also some tools that are being developed by Red Hat that will make your life much easier is running VMs such as Cobbler (http://fedorahosted.org/cobbler) and oVirt (http://ovirt.org). Cobbler is an install server capable of installing almost any flavor of Linux or Windows onto either virtual of bare metal boxes. It also supports KVM, Xen, Qemu and VMware - but not VBox. oVirt will manage VMs across multiple several boxes and allow some very advanced features such as live migration and resource pools.

This is a good place to get started with VMs in Fedora 10 (link (http://fedoraproject.org/wiki/Virtualization_Quick_Start)).

The choice, of course, is yours (a feature of Linux).

17th March 2009, 09:36 PM
Thank you GrapeShot for the information.

My first try at virtualization with Fedora was not very good (I am new in Linux) . So far, VMWare is working fine for me.

I will go back to Linux native virtualization as soon as I learn enough. So thanks again for the links.

Have fun !!!

20th March 2009, 06:27 PM
Hello everybody

what file system would you suggest to access the physical hard drives?

I tried an NFS and a Samba server on the host so the guests can have storage space.

Is there anything better?

Thank you for your help