Moving to KVM virtual machines

By Leo Gaggl

April 15, 2018

Installing VirtualBox is getting increasingly painful on Ubuntu due to the problems with UEFI Secure Boot and the VirtualBox kernel modules. Another reason for an alternative is that running VirtualBox VM’s completely in the background is not as straightforward as it could be.

From the available alternatives I looked into (VMWare, Xen & KVM) it was KVM that fitted my needs (casual VM usage with mostly headless VM’s for testing purposes). Main reasons:

Well supported by Ubuntu
Easy, straightforward install
Background VM’s are simple as
Moving VM’s from one host to another is a breeze

Checking system

To check if the CPU can actually support

egrep -c '(svm|vmx)' /proc/cpuinfo

If the number returned is > 0 your systems should be capable to run.

You will also enable your BIOS for virtualisation (in Security settings of most BIOS’s) if that has not already be done. You will get an error if not enabled if you are trying to run an install. The Install of KVM will work fine.

Installation

sudo apt-get install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils virt-manager sudo addgroup libvirtd sudo adduser libvirtd sudo service libvirtd start sudo service libvirtd status sudo virt-manager

Moving VM’s to another host

Source Host

virsh shutdown VMNAME virsh dumpxml VMNAME > /tmp/VMNAME.xml scp /tmp/VMNAME.xml TARGETHOST:/tmp/VMNAME.xml scp /var/lib/libvirt/images/VMNAME.qcow2 TARGETHOST:/var/lib/libvirt/images/VMNAME.qcow2

Target Host

virsh define /tmp/vm.xml virsh start vm

Once you have confirmed operation you probably want to remove the source VM from the Source Host.

virsh undefine VMNAME rm /var/lib/libvirt/images/VMNAME.qcow2