Creating and Starting KVM Virtual Machine: Basic Steps

This is just a note for docummenting the basic steps to create and start KVM virtual machines on Linux systems

1. Make a plan for virtual machine resources. For this, we should query host resources.

   
       # show available disk spaces
       df -h
       # show available memory
       free -m
       # CPUs
       lscpu
       

2. Assume we are installing an Ubuntu server system. We shall download the ISO image for the system, e.g.,

   
       wget \
         https://releases.ubuntu.com/22.04.1/ubuntu-22.04.1-live-server-amd64.iso \
         -O /var/lib/libvirt/images/ubuntu-22.04.1-live-server-amd64.iso
       

3. Create a virtual disk for the virtual machine, e.g.,

   
       sudo truncate --size=10240M /var/lib/libvirt/images/officeservice.img
       

4. Decide how we should configure the virtual machine network. First, we query existing ones:

   
       virsh --connect qemu:///system  net-list --all
       

5. Now create a virtual machine and set up Ubuntu Linux on it, e.g.,

   
       sudo virt-install --name ubuntu \
       --description 'Ubuntu Server LTS' \
       --ram 4096 \
       --vcpus 2 \
       --disk path=/var/lib/libvirt/images/officeservice.img,size=10 \
       --osinfo detect=on,name=ubuntu-lts-latest \
       --network network=default \
       --graphics vnc,listen=127.0.0.1,port=5901 \
       --cdrom /var/lib/libvirt/images/ubuntu-22.04.1-live-server-amd64.iso  \
       --noautoconsole \
       --connect qemu:///system
       

6. Suppose that you connect to Linux host via ssh via a Windows host. We cannot directly access the console of the virtual machine (that is at 127.0.0.1:5901 via VNC). In this case, we tunnel to the Linux host (assume its host name is LinuxHost) from the Windows host:

   
       ssh -L 15901:localhost:5901 LinuxHost
       

7. We can now access the control via a VNC Viewer at the Windows host at localhost:15901.
8. Once Ubuntu installation is over, we would lose the VNC connectivity. But, we can list the virtual machine created.

   
       sudo virsh --connect qemu:///system list --all
       

9. To start the virtual machine, we run

   
       sudo virsh --connect qemu:///system  start ubuntu
       

10. To make the virtual machine to start when we boot the host, set the virtual machine to be autostart, e.g.,

    
    	virsh --connect qemu:///system autostart ubuntu
    	

References

1. https://docs.fedoraproject.org/en-US/quick-docs/getting-started-with-virtualization/
2. https://ubuntu.com/blog/kvm-hyphervisor
3. https://askubuntu.com/questions/160152/virt-install-says-name-is-in-use-but-virsh-list-all-is-empty-where-is-virt-i
4. https://www.cyberciti.biz/faq/rhel-centos-linux-kvm-virtualization-start-virtual-machine-guest/
5. https://www.cyberciti.biz/faq/howto-linux-delete-a-running-vm-guest-on-kvm/