Linux virtual machine with KVM from the command line

If we want to raise virtual machines in a Linux environment that does not have a graphical environment, we can raise virtual machines using the command line with a XML template. This article explains how the deployment performed with Ansible-libvirt at KVM, Ansible and how to deploy a test environment works internally Install Qemu-KVM and Libvirt First: we must to install libvirt and Qemu-KVM. In Ubuntu / Debian is installed with: And in CentOS / Redhat with: To launch the service we must do: $ sudo systemctl enable libvirtd && sudo systemctl start libvirtd Configure a network template Libvirt provides us with a powerful tool for managing virtual machines called ‘virsh’, which we must use to be able to manage KVM virtual machines from the command line. For a virtual machine we mainly need three elements, the first is a network configuration that provides IP to virtual machines via DHCP. To do this libvirt needs XML template like the next template (which we will designate “net.xml”): Whose main elements are: NETWORK_NAME: Descriptive name that we are going to use to designate the network, for example, “test_net” or “production_net”. BRIDGE_NAME: Each network creates an interface on the host server that will serve as gateway of the input/output packets of that previous network to the outside. Here we assign a descriptive name that let as identify the interface. IP_HOST: The IP that such interface will have on the host server and that will be the gateway of the virtual machines. NETWORK_MASK: Depends on the network, usually for testing must be use a class C (255.255.255.0) BEGIN_DHCP_RANGE: To assign IPs to virtual machines using libvirt, there are an internal DHCP server (dnsmasq based), here we define the first IP of the range that we can serve to virtual machines. END_DHCP_RANGE: And here we define the last IP that virtual machines can obtain. Preparing the operating system image The second element is the virtual machine image, this image can be created or downloaded, the second is recommended to reduce the deployment time. An image source for virtual machines with KVM / libvirt is Vagrant (https://app.vagrantup.com/boxes/search?provider=libvirt), to obtain an image of the virtual machine that interests us, we must download from https://app.vagrantup.com/APP_NAME/boxes/APP_TAG/versions/APP_VERSION/providers/libvirt.box where APP_NAME is the name of the application we want to download (e.g. debian), APP_TAG is the distribution of this application (e.g. stretch64) and finally APP_VERSION is the version of the application (e.g. […]

Posts navigation

1 2
Scroll to top