Review of KVM virtualization under Ubuntu server 12.04

In my discussion of my home-based server, setting up an Ubuntu 12.04 server and using its "native" KVM virtualization technology was one virtualization solution.

Up to this point, I had never tried KVM, although I had dabbled a bit with QEMU which appears to be a part of KVM.

Installation

Installing Ubuntu 12.04 from USB had one wrinkle. I found that if I used YUMI to create a bootable USB from an .iso, the Ubuntu installer had trouble finding the "CD-ROM" for the installer files. Creating the bootable USB with Unetbootin solved this problem.

Installing KVM in the default Ubuntu 12.04 server was relatively straight-forward. Here are a couple posts I found useful for this :

https://help.ubuntu.com/community/KVM/Installation

http://www.itworld.com/virtualization/216949/crash-course-virtualization...

There was one wrinkle alluded to in the above docs. It seemed like I needed to add myself to the following groups to get virtualization to work :


$ sudo adduser `id -un` kvm
$ sudo adduser `id -un` libvirtd


I wanted to have a light-weight windowing system on my HP MicroServer, so I went ahead and added LXDE and started the KVM virtual machine manager with the following :


$ sudo apt-get install lxde
$ virt-manager -c qemu:///system kvmhost


User experience

The KVM GUI manager worked pretty well, considering it's "free" software. I was able to setup VMs pretty easily, and they worked pretty much without a hitch.

Still, there seemed to be some loose ends. Help in the VM setup wizard was pretty sparse. I got a couple inexplicable warnings or error messages. I had trouble switching networking from NAT to bridged.

Most of this can probably be worked through by reading the docs. It seems like the Linux community is just now starting to coalesce around KVM as the leading virtualization solution, so some of these rough edges will probably disappear over time.

Lack of snapshots

I didn't see any snapshot controls from the KVM VM management GUI. A quick web search turned up the following resource (among others) regarding KVM snapshots :

http://redes-privadas-virtuales.blogspot.com/2011/05/taking-snapshots-on...

The above is a command line method to create snapshots. This is fine, and definitely desired for automated processes, but not really suitable for casual or ad hoc use.

Cloning

Cloning was one area where KVM did pretty well. In the VM management GUI, you can simply choose to "Clone" a VM, and it's a simple process. However, I seemed to have hit a snag with respect to virtual network cards. It seemed like the MAC addresses may have been duplicated, so I was getting some kind of network error on boot. I removed and re-added a network card, switched from bridged networking back to the default NAT, and rebooted and things went OK.

Performance

I provide details on performance, but relative to Hyper-V and ESXi, KVM was a bit slower in both CPU-intensive I/O-intensive tests.