Kvm Guests on the bin

KVM Guests: Graceful Shutdown

Mon, 06 Feb 2012 00:00:00 +0000

So a fairly trivial (but critical) aspect of using KVM is of course performing graceful shutdowns of your domains, without having to reach inside of the guest to perform the shutdown. Now when it comes to turning off your guests you have two ways of proceeding (with virsh)…

bash

virsh destroy vmname

Which is a HARD power off of your guest. This is the same as pulling the power cord from the wall, nothing is shutdown, but the noise stops just the same. This method can result in data corruption if writes are interrupted.

KVM Guests: Install VirtIO Drivers for Windows Guests

Tue, 22 Mar 2011 00:00:00 +0000

Windows guests on the KVM hypervisors can get a very large kick in the pants when it comes to performance if you install the drivers necessary to leverage the VirtIO bus. So first here are the necessary download links so that you can download the drivers.

http://alt.fedoraproject.org/pub/alt/virtio-win/latest/images/bin/virtio-win-1.1.16.iso

http://alt.fedoraproject.org/pub/alt/virtio-win/latest/images/

Inside of the ISO we will find four directories Balloon, NetKVM, vioserial, and viostor. We are only concerned with viostor and NetKVM, for the storage and networking drivers. Vioserial is a serial interface which essentially lifts the single serial device limitation within KVM, and Balloon is a balloon memory driver I personally do not find this necessary due to the efficacy of the Kernel Samepage Merging (KSM) which is essentially memory deduplication.

KVM Guests: Manipulating Libvirt XML for Guest Creation

Tue, 15 Mar 2011 00:00:00 +0000

Today we are going to discuss using the underlying XML which libvirt uses to define a VM to either create VMs or to make simple changes. This method has the advantage of more control over what you are creating, although it is more manual. Now first off, when you use virt-install, virt-manager, or another tool which uses libvirt under the covers an XML file is created for every VM that you define, libvirt stores these in /etc/libvirt/qemu/ and names them vmname.xml.

KVM Guests: Using Virt-Install to Install VMs from a CD or ISO Image

Mon, 14 Mar 2011 00:00:00 +0000

In my previous article KVM Guests: Using Virt-Install to Import an Existing Disk Image we discussed how to use virt-install to import an existing disk image, which already has an OS installed into it. Additionally in KVM Guests: Using Virt-Install to Install Debian and Ubuntu Guests I documented how to initiate an install directly off of the apt mirror of your choice for Debian and Ubuntu Guests using virt-install. In this article we will use virt-install to create a guest and begin the installation using a CD or ISO image for installation media.

KVM Guests: Using Virt-Install to Import an Existing Disk Image

Tue, 08 Mar 2011 00:00:00 +0000

In my previous article KVM Guests: Using Virt-Install to Install Debian and Ubuntu Guests we identified how we can use the virt-install command to create a KVM VM and instead of using an iso or physical cd for the install media we can instead use a boot image from an apt mirror via http. Now obviously this does not harness the true power of the virt-install command. Today we will discuss how we can take an existing disk image and import it as a VM with the appropriate devices, this would most commonly be done with sysprepped Windows images, to speed up deployment. Though these instructions will easily work with any OS.

KVM Guests: Using Virt-Install to Install Debian and Ubuntu Guests

Wed, 02 Mar 2011 00:00:00 +0000

I like to be able to spin up a VM without looking for CD media so for a while now I have been using ISO images for all of my installs directly, however I found my self scurrying around “digitally” looking for the correct iso in much the same way I used to scurry about looking for physical CDs, except I was not physically moving. So anyways the time was wasted either way, I figured it is time that I find a better (read: lazier) way to do this. So the idea is that since the apt package manager contains all the packages and files needed to install and upgrade a system, we ought to be able to find a way to initiate the install over the wire.