KVM short setup

Short tutorial for installing and running KVM supervisor and creating VMs with Ubuntu Cloud Image.

Requirements

Ubuntu-based computer with hardware virtualization support.

This tutorial actual for Ubuntu 22.04 LTS.

Check support (result should be more than 0):

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

Installation

Install KVM related packages.

sudo apt install qemu-kvm virtinst libvirt-daemon-system cloud-image-utils

Check service libvirtd is running.

sudo systemctl status libvirtd

Creating base OS image

Create directory for base OS images.

sudo mkdir /var/lib/libvirt/images/base

Get Ubuntu Minimal Cloud Image and move into directory.

wget https://cloud-images.ubuntu.com/minimal/releases/jammy/release/ubuntu-22.04-minimal-cloudimg-amd64.img

Check image has file format qcow2.

qemu-img info ubuntu-22.04-minimal-cloudimg-amd64.img

Move image into directory.

sudo mv ubuntu-22.04-minimal-cloudimg-amd64.img /var/lib/libvirt/images/base/ubuntu-22.04.qcow2

Creating virtual machines

Get createvm from this repository and place into ~./local/bin directory.

Also make it executable.

wget https://github.com/devgkz/kvm-short-setup/archive/refs/heads/main.zip
unzip main.zip
mv kvm-short-setup-main/createvm ~/.local/bin
chmod +x ~/.local/bin/createvm

Open createvm and check config block, edit if nesessary.

By default script will create VM with 1vcpu, 512MiB RAM, 5G disk space, default "user" ans "pass". Also will be used your local key ~/.ssh/id_rda.pub for authentication. Check it is exists.

Create new virtual machine, for example with id "vm1" and IP 192.168.122.101

createvm vm1 101

If IP not specified will be used automatic network config.

After creation, VM started automatically. Check it is running.

sudo virsh list

 Id   Name   State
----------------------
 1    vm1    running

Check the VM network configured properly.

sudo virsh domifaddr vm1  --source arp

 Name       MAC address          Protocol     Address
---------------------------------------------------------------
 vnet9      52:54:00:e1:4c:2c    ipv4         192.168.122.101/0

Now connect to VM via SSH.

ssh user@192.168.122.101

Useful KVM commands

List of running VMs.

sudo virsh list

List all VMs.

sudo virsh list --all

Get console for vm1.

sudo virsh console vm1

Shutdown, reboot, start vm1.

sudo virsh shutdown vm1
sudo virsh reboot vm1
sudo virsh start vm1

Remove VM from supervisor.

sudo virsh undefine vm1

Links, read more

Ubuntu Cloud Images https://cloud-images.ubuntu.com/

Cloud-init Docs https://cloudinit.readthedocs.io/

Ubuntu KVM/Networking https://help.ubuntu.com/community/KVM/Networking