Install KVM / QEMU on Debian
Follow the steps below to install KVM Virtualization on Debian Linux system. All KVM packages for Debian are available on upstream repositories. The apt package manager is used for all packages installation.
sudo apt update
sudo apt -y install qemu-kvm libvirt-daemon bridge-utils virtinst libvirt-daemon-systemLoad and enable the vhost_net module.
$ sudo modprobe vhost_net
$ lsmod | grep vhost
vhost_net 24576 0
tun 49152 1 vhost_net
vhost 49152 1 vhost_net
tap 28672 1 vhost_net
$ echo vhost_net | sudo tee -a /etc/modules Let’s also install useful Virtual Machine management tools.
sudo apt -y install vim libguestfs-tools libosinfo-bin qemu-system virt-managerThis will give you tools similar to Linux ls, cat, top command for use with Virtual Machines.
Create KVM Bridge on Debian (Optional)
For your Virtual Machines to talk to the outside world, a Linux bridge is required. Installation of KVM on Debian creates a Linux bridge called virbr0. This can be used for all test environments.
But if you want to your VMs to be accessible over the network, you’ll need to create a bridge on physical network interface attached to your machine.
Create one on your Debian server/workstation like below.
sudo vim /etc/network/interfacesMy bridge configuration uses a network interface (ens33) to create a Linux bridge called br1. Replace the values provided with yours.
# Primary network interface
auto eno1
iface eno1 inet manual
# Bridge definitions
auto br0
iface br0 inet static
bridge_ports eno1
bridge_stp off
address 192.168.1.2
network 192.168.1.0
netmask 255.255.255.0
broadcast 192.168.1.255
gateway 192.168.1.1
dns-nameservers 172.20.30.252 172.20.30.251Reboot your machine for the network configuration changes to take effect.
sudo rebootConfirm ip network details.
$ ip ad
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host noprefixroute
valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master br0 state UP group default qlen 1000
link/ether 1c:69:7a:61:da:e9 brd ff:ff:ff:ff:ff:ff
altname enp0s31f6
3: wlp0s20f3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 08:71:90:27:5b:be brd ff:ff:ff:ff:ff:ff
4: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 26:8f:ab:9f:8b:85 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.2/24 brd 192.168.1.255 scope global br0
valid_lft forever preferred_lft forever
inet6 fe80::248f:abff:fe9f:8b85/64 scope link
valid_lft forever preferred_lft foreverCreate Virtual Machine on KVM
You can use Virtual Machine Manager GUI to create an instance on KVM or via virt-install command line tool.
For virt-install, installation snippet is shared below.
sudo virt-install \
--name deb12 \
--ram 2048 \
--vcpus 2 \
--disk path=/var/lib/libvirt/images/deb12-vm.qcow2,size=20 \
--os-type linux \
--os-variant debian12 \
--network bridge=br0 \
--graphics none \
--console pty,target_type=serial \
--location 'http://ftp.debian.org/debian/dists/bookworm/main/installer-amd64/' \
--extra-args 'console=ttyS0,115200n8 serial'This will download kernel and initrd image before starting installation.
The installation process will start shortly. Follow installation prompts for Debian system on KVM.
Using Cockpit Web Console
Cockpit enables you to manage your instances and Podman containers from a web console. Install it by running the following commands:
sudo apt install cockpit cockpit-machines cockpit-podmanThen start and enable the service.
sudo systemctl enable cockpit.socket && sudo systemctl start cockpit.socketConfirm service status:
$ systemctl status cockpit.socket
● cockpit.socket - Cockpit Web Service Socket
Loaded: loaded (/lib/systemd/system/cockpit.socket; enabled; preset: enabled)
Active: active (running) since Wed 2024-07-23 05:48:48 EDT; 11min ago
Triggers: ● cockpit.service
Docs: man:cockpit-ws(8)
Listen: [::]:9090 (Stream)
Tasks: 0 (limit: 28431)
Memory: 84.0K
CPU: 9ms
CGroup: /system.slice/cockpit.socket
July 23 05:48:48 osp01.home.cloudlabske.io systemd[1]: Starting cockpit.socket - Cockpit Web Service Socket...
July 23 05:48:48 osp01.home.cloudlabske.io systemd[1]: Listening on cockpit.socket - Cockpit Web Service Socket.Access cockpit web interface on https://server-ip-address:9090
We also have a guide on Virtual Machine’s installation on KVM with Terraform.
Also check related KVM articles:
Would’ve been nice to see some more explanation about the options given in the virt-install command, or at least a pointer to a reference. I can well imagine people don’t all want to use your preferences.