I’ve been using KVM and virt-install to manage virtual machines on one of my servers, this post shows how to use virt-install.
According to the package management system I’m having the following packages installed:
root@edgewalker ~ # dpkg -l | grep virt
ii libvirt-bin 1.1.1-0ubuntu8.1 amd64 programs for the libvirt library
ii libvirt0 1.1.1-0ubuntu8.1 amd64 library for interfacing with different virtualization systems
ii munin-libvirt-plugins 0.0.6-1 all Munin plugins using libvirt
ii openvpn 2.3.2-4ubuntu1 amd64 virtual private network daemon
ii python-libvirt 1.1.1-0ubuntu8.1 amd64 libvirt Python bindings
ii qemu-kvm 1.5.0+dfsg-3ubuntu5 amd64 QEMU Full virtualization on x86 hardware (transitional package)
ii virt-top 1.0.7-1 amd64 show stats of virtualized domains
ii virtinst 0.600.4-2ubuntu2.1 all Programs to create and clone virtual machines
Storage-wise I’m using a LVM volume group called ‘vg0’ (which was imported into the libvirt configuration).
How to use virt-install
To setup a new guest machine I’m using the following command:
$ virt-install -n virtual_machine_name -r 4096 --os-type=linux --os-variant=debianwheezy --disk pool=vg0,size=40,bus=virtio,sparse=false,cache=none,io=native -w bridge=virbr0,model=virtio --graphics none -l http://ftp.debian.org/debian/dists/wheezy/main/installer-amd64/ --autostart -x console=ttyS0,115200n8
That’s mostly it. The parameters configure the following
| Parameter | Value | Why? |
|---|---|---|
| -n | virtual_machine_name | the name of the virtual machine, d’oh |
| -r | 4096 | virtual memory size, this would be 4GB |
| -l, -os* | .. | which operating system to install |
| –disk | .. | create a new LVM volume with 40GB, use virtio drivers for higher performance |
| -w | .. | network configuration, use the default bridge |
| –graphics | none | we don’t need not graphical user interface |
| –autostart | none | automatically start installation |
| -x console | .. | also create a virtual console, this will allow us to finish installation |
The host-bridge setup (created by the debian installation) will assign a private IP address to the virtual machine through DHCP. I’m using the virtio drivers as those should yield better performance than the rest.