I run many virtual machines on KVM and VirtualBox. I typically clone an existing VM that is already set up for the project or service I’m working on. These are the steps I take on KVM on Linux (Ubuntu) hosts to clone and deploy a guest VM.
On the host
Suspend the VM you’re copying
sudo virsh shutdown source_VM
Clone the source VM with a new name
sudo virt-clone --original source_VM --name destination_VM --file /var/lib/libvirt/images/destination_VM.qcow2
Start the source VM back up
sudo virsh start source_VM
Prepare the new VM for service
sudo virt-sysprep -d destination_VM --hostname destination_VM --enable customize,user-account,ssh-hostkeys,net-hostname,net-hwaddr,machine-id --keep-user-accounts your_username --keep-user-accounts root
Start the new VM
sudo virsh start destination_VM
On the guest
Fix up SSH
sudo dpkg-reconfigure openssh-server
Restart the guest
sudo reboot