- The author decided to move away from Vagrant to using KVM and libvirt for virtual machine management, feeling it was overly complex and redundant since Linux can handle virtualization natively.
- KVM allows the Linux kernel to function as a hypervisor, while libvirt is a library that manages KVM and other virtualization platforms, with virsh as a command-line interface for interacting with libvirt.
- A practical example is given for creating a preseeded Debian VM using virt-install, which automates installation with predefined answers and handles network connectivity, mounting, and SSH agent forwarding.
- Key steps include checking KVM module status, installing libvirt and virsh, using preseed files for deterministic builds, and troubleshooting issues like serial output problems after OS upgrades.
- The author highlights the benefits of using libvirt for unified virtualization management and shares useful commands for VM lifecycle control, network setup, and file system mounting.