KVM : Create Virtual Machine

	Install GuestOS and Create a Virtual Machine. This example shows to create VM with installing Debian 13.
[1]	On this example, Download an ISO file of Debian 13 on a directory first and Install GuestOS from the ISO on the text mode. It's OK on the console or remote connection via SSH and so on. Furthermore, Virtual Machine's images are placed at [/var/lib/libvirt/images] by default as a Storage Pool, however this example shows to create and use a new Storage Pool. (OK to use any place you like)

# create a Storage Pool directory root@dlp:~#  mkdir -p /var/kvm/images root@dlp:~# virt-install \ --name debian13 \ --ram 4096 \ --disk path=/var/kvm/images/debian13.img,size=20 \ --vcpus 2 \ --os-variant debian13 \ --network bridge=br0 \ --graphics none \ --console pty,target_type=serial \ --location /home/debian-13.0.0-amd64-DVD-1.iso \ --extra-args 'console=ttyS0,115200n8 serial' # installation starts # after this, installation proceeds with the common procedure Starting install... Retrieving file vmlinuz... | 6.5 MB 00:00 Retrieving file initrd.gz... | 17 MB 00:00 Allocating 'debian13.img' | 20 GB 00:00 ..... ..... # once the installation is complete, return to the host and shut down the guest root@dlp:~#  virsh shutdown debian13 # mount the guest area and enable the service root@dlp:~#  guestmount -d debian13 -i /mnt root@dlp:~#  ln -s /mnt/lib/systemd/system/getty@.service /mnt/etc/systemd/system/getty.target.wants/getty@ttyS0.service root@dlp:~#  umount /mnt # restart the VM and if you can connect to the console, the installation is complete root@dlp:~#  virsh start debian13 --console Debian GNU/Linux 13 debian ttyS0 debian login:

The example of options above means like follows. There are many options for others, make sure with [man virt-install]. --name specify the name of Virtual Machine --ram specify the amount of memory of Virtual Machine --disk path=xxx,size=xxx [path=xxx] : specify the location of disks of Virtual Machine (default is [/var/lib/libvirt/images]) [size=xxx] : specify the amount of disk of Virtual Machine --vcpus specify the virtual CPUs --os-variant specify the kind of GuestOS possible to show the list of available OS with the command below [# osinfo-query os] --network specify network type of Virtual Machine --graphics specify the kind of graphics possible to specify spice, vnc, none and so on --console specify the console type --location specify the location of installation source where from --extra-args specify parameters that are set in Kernel

[2]	For installing on text mode, it's the same with common installation procedure. After finishing installation, restart computer and then login prompt is shown like follows.

Debian GNU/Linux 13 debian ttyS0 debian login: root Password: Linux debian 6.12.38+deb13-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.38-1 (2025-07-16) x86_64 The programs included with the Debian GNU/Linux system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. root@debian:~#

[3]	Move to GuestOS to HostOS with Ctrl + ] key. Move to HostOS to GuestOS with a command [virsh console (name of virtual machine)].

root@debian:~# # Ctrl + ] key root@dlp:~# # Host's console root@dlp:~# virsh console debian13 # switch to Guest's console Connected to domain 'debian13' Escape character is ^] # Enter key root@debian:~# # Guest's console

[4]	It's easy to replicate a copy VM from current VM with a command below.

root@dlp:~#  virt-clone --original debian13 --name template --file /var/kvm/images/template.img Allocating 'template.img' | 20 GB 00:00:05 Clone 'template' created successfully. # disk image root@dlp:~#  ll /var/kvm/images/template.img -rw------- 1 root root 5321195520 Aug 21 09:24 /var/kvm/images/template.img # configuration file root@dlp:~#  ll /etc/libvirt/qemu/template.xml -rw------- 1 root root 6730 Aug 21 09:24 /etc/libvirt/qemu/template.xml