Consider this:

*** The below command make you become root, but does NOT inherit root’s environment variables. Modprobe, ifconfig, etc, would all require a full path.
$ su

**** The below command makes you root AND gives you root’s environment, namely $PATH/
$ su -

So try that… simply add the space-hyphen after su, and then modprobe and other will work without any additional work.

It is clear you have worked out some of the finer points of QEMU/KVM to solve problems that users such as Stephen O’Grady and myself have experienced.

I have been using Fedora for 2 years as my main desktop OS, so I can get around the OS okay. However QEMU/KVM presented so many problems I gave up and went back to using VMware Server.

Would you have, or be able to direct us to a URL that has a good HOWTO on setting up QEMU/KVM on Fedora?

I followed the guide here: http://www.phoronix.com/scan.php?page=article&item=656&num=1 but once I started trying to install a Guest OS I had repeated problems.

At various points during exploration I was not fully happy with resulting virtual machines definitions that virt-manager automatically generated.

You can use “virsh undefine VM_NAME”, “virsh dumpxml VM_NAME”, “virsh define VM_DEF_FILE.xml”, and various others to remove/add/edit virtual machine definitions (e.g., to boot up cdrom-liveCD-rescue-disk instead of from hard drive, to mount additional hard drives on VM), start/stop networks, etc. You’ll need to learn the XML format for VM definitions.

Also useful is the QEMU console where you can issue commands to the virtual machine’s virtual hardware drivers (?) to change mounted CD-ROM images, send special key combinations, etc. (use commands such as ‘echo “sendkey ctrl+alt+delete” > /dev/pts/3′ and then ‘cat /dev/pts/3′ + CTRL-C to see results). There’s a trick to finding the /dev/pts/NNN the particular virtual machine is listening on.

Using Virtual Machine Manager, libvirtd, qemu, and KVM I have a complete firewalled “corporate IT” system running on a quad-core 8GB Intel-VT machine:

[A] 5 separate internal networks
[B] one being an internal Windows network
with a WinXP and 3 separate
Win2003-Server machines (and I can even
VPN to this network from outside the
real physical hosting box)
[C] running CentOS, Fedora on other machines
[D] 10 virtual machines defined, 6 typically running
[E] beautiful performance
[F] all machines fully hardware-accelerated
(both i386/i686 and x86_64)

I’d like to install a fully emulated sparc-based Solaris 10 (or even Solaris 9) OS … then I’d be happy. A full software dev/demo environment, a hosting platform for multiple websites on different external IP addresses. Fully firewalled.

It’s a pain to figure what works but it’s beautiful once you get the hang of it, much better than Xen.

Because VMware is stable and most OSes just work, I have no problems using it. FYI server 2008 IS labled experimental so there will almost always be issues associated with that. BSODs are common at that point.

Virtual Box is great for some uses, but they don’t always support features that VMware does like x64 multi-CPU, SCSI disk support (if you need that).

Fedora’s Xen based Virtualization is not exactly up to snuff. The underlying technology has potential, but the mangement tools are still lacking alot of polish and usability.

Normally, if I am not an expert in a field, and if I did not know precisely what I was doing, I would contact, via the web forums, someone who had been through the experience beforehand.

My view is that the author suffered from stress due to time constraints, and could not do his analysis as it should have been done.

Add to sources.list
deb http://archive.canonical.com/ubuntu gutsy partner

apt-get install vmware-server

So, to compare them is, IMHO, completely mistaken.

Second: the virtuals are also different products with sometimes different end market goals. I agree with the poster above who mentioned Virtual Box. While Xen is a good server choice for real-world production, for myself, doing little projects that require a working instance of WIndows, VB is easier to setup, destroy, rebuild and mess with. The community support is outstanding and the project is building an excellent product that is aware of freedom and freedom issues. or most of the world VB is a good solution at the moment> Caveat? everythinjg is changing fast, so next week I might have a different opinion.