FAST Win7 KVM VirtIO{Disk-Net} Install

Everyone who has to use Windows, please let's at least keep it contained inside a virtual machine! In this article I'll demo how to "Install Windows7 over Ubuntu 11.04 Natty, using KVM with System Disk over VirtIO". Quoting the libvirt wiki "Virtio is a Linux standard for network and disk device drivers where just the guest's device driver "knows" it is running in a virtual environment, and cooperates with the hypervisor. This enables guests to get high performance network and disk operations, and gives most of the performance benefits of paravirtualization"

Here's a little convenience script to download virtio Windows drivers and launch virt-install to Install Windows. Copy/Paste this script into an empty folder, chmod +x it, and run it.

#!/bin/sh
WINISO=/path/to/win7.iso    #Windows ISO
INSTALLDISK=win7virtio.img  #Disk location. Can be LVM LV
VFD=http://alt.fedoraproject.org/pub/alt/virtio-win/latest/images/bin/virtio-win-1.1.16.vfd
DRVRISO=http://alt.fedoraproject.org/pub/alt/virtio-win/latest/images/bin/virtio-win-1.1.16.iso

[ -e $(basename $VFD) ]     || wget $VFD
[ -e $(basename $DRVRISO) ] || wget $DRVRISO
[ -e $INSTALLDISK ]         || qemu-img create $INSTALLDISK 30G

sudo virt-install -c qemu:///system --virt-type kvm --name win7virtio --ram 1024 --disk path="$INSTALLDISK",bus=virtio \
--disk $(basename $VFD),device=floppy --os-variant win7 --cdrom $(basename $DRVRISO) --cdrom "$WINISO" --vcpus 2

et voila Windows installer kicks in, we're greeted with the usual



Next the welcome screen, and agree on the license agreement (if you want!)


In this next screenshot, we see how Windows Installer does not see any "disks". This is because Windows now does not have any drivers for the virtio disk that we attached!


Let's fix that, clicking "Load Driver" and clicking OK, Windows starts reading the VFD virtual floppy image we attached, and detects the driver


Clicking Next, Windows can now see the virtio disk

Then it's business like usual

After installation completes, be sure to check the device manager and confirm the disk (and network) are both using optimized virtio drivers


et voila, Windows in its full glory running over optimized virtio drivers. The only part that sucks is desktop VNC performance, something that I'll probably write about very soon :)