Arch Linux KVM/libvirt VM Lab Guide

With br0 working, use libvirt/KVM + UEFI + qcow2 + VirtIO + VNC for installation, then install XFCE + xrdp inside each guest. This gives you VNC as a rescue/console connection and RDP for normal desktop use.

This guide uses Ubuntu 26.04, Rocky Linux 10, and AlmaLinux 10. For an Intel N200 host with 8 GB RAM, start each VM with 2 GB RAM / 2 vCPUs and avoid running all three heavily at once.

1. ISO and VM storage

Recommended layout:

/var/lib/libvirt/
├── iso/
│   ├── ubuntu-26.04-live-server-amd64.iso
│   ├── Rocky-10-x86_64-minimal.iso
│   └── AlmaLinux-10-x86_64-minimal.iso
└── images/
    ├── ubuntu.qcow2
    ├── rocky.qcow2
    └── alma.qcow2

Create the ISO directory:

sudo mkdir -p /var/lib/libvirt/iso
sudo chmod 755 /var/lib/libvirt/iso

VM disks will go in /var/lib/libvirt/images/.

Check ISOs:

ls -lh /var/lib/libvirt/iso/

Copy downloaded ISOs:

sudo cp ~/Downloads/*.iso /var/lib/libvirt/iso/

2. Create Ubuntu

sudo virt-install \
  --connect qemu:///system \
  --name ubuntu \
  --memory 2048 \
  --vcpus 2 \
  --cpu host-passthrough \
  --disk path=/var/lib/libvirt/images/ubuntu.qcow2,size=30,format=qcow2,bus=virtio \
  --cdrom /var/lib/libvirt/iso/ubuntu-26.04-live-server-amd64.iso \
  --network bridge=br0,model=virtio \
  --boot uefi \
  --graphics vnc,listen=127.0.0.1 \
  --noautoconsole

Check:

sudo virsh list --all
sudo virsh vncdisplay ubuntu

:0 means port 5900, :1 means 5901, and so on.

If VNC is listening only on localhost, tunnel it from another machine:

ssh -L 5900:127.0.0.1:5900 youruser@192.168.1.17

Connect the VNC client to 127.0.0.1:5900.

3. Create Rocky Linux

Use the exact ISO filename present in /var/lib/libvirt/iso/:

sudo virt-install \
  --connect qemu:///system \
  --name rocky \
  --memory 2048 \
  --vcpus 2 \
  --cpu host-passthrough \
  --disk path=/var/lib/libvirt/images/rocky.qcow2,size=30,format=qcow2,bus=virtio \
  --cdrom /var/lib/libvirt/iso/Rocky-10-x86_64-minimal.iso \
  --network bridge=br0,model=virtio \
  --boot uefi \
  --graphics vnc,listen=127.0.0.1 \
  --noautoconsole

Then:

sudo virsh vncdisplay rocky

If it reports :1, tunnel port 5901:

ssh -L 5901:127.0.0.1:5901 youruser@192.168.1.17

4. Create AlmaLinux

sudo virt-install \
  --connect qemu:///system \
  --name alma \
  --memory 2048 \
  --vcpus 2 \
  --cpu host-passthrough \
  --disk path=/var/lib/libvirt/images/alma.qcow2,size=30,format=qcow2,bus=virtio \
  --cdrom /var/lib/libvirt/iso/AlmaLinux-10-x86_64-minimal.iso \
  --network bridge=br0,model=virtio \
  --boot uefi \
  --graphics vnc,listen=127.0.0.1 \
  --noautoconsole

Then:

sudo virsh vncdisplay alma

Do not assume VNC display numbers stay fixed; always check with virsh vncdisplay.

5. After installation: remove/eject the ISO

Inspect disks:

sudo virsh domblklist ubuntu

Example:

Target   Source
--------------------------------------------------
vda      /var/lib/libvirt/images/ubuntu.qcow2
sda      /var/lib/libvirt/iso/ubuntu-26.04-live-server-amd64.iso

You can edit the VM with:

sudo virsh edit ubuntu

or use virsh change-media to eject the virtual CD-ROM after identifying its target.

6. Ubuntu: XFCE + RDP

Inside Ubuntu:

sudo apt update
sudo apt upgrade -y
sudo apt install xfce4 xfce4-goodies -y
sudo apt install xrdp -y
sudo systemctl enable --now xrdp
echo "startxfce4" > ~/.xsession
systemctl status xrdp

Find the guest IP:

hostname -I

Because the VM is attached to br0, it should receive a normal 192.168.1.x LAN address. Connect an RDP client to that IP on port 3389.

7. Rocky Linux: XFCE + RDP

Inside Rocky:

sudo dnf update -y
sudo dnf group list
sudo dnf search xfce

If the XFCE group is available:

sudo dnf group install "Xfce" -y

Install and enable xrdp if available:

sudo dnf install xrdp -y
sudo systemctl enable --now xrdp

If firewalld is enabled:

sudo firewall-cmd --permanent --add-port=3389/tcp
sudo firewall-cmd --reload

Set the XFCE session:

echo "startxfce4" > ~/.Xclients
chmod +x ~/.Xclients

Find the IP:

hostname -I

If Rocky 10 reports that XFCE or xrdp is unavailable, verify repository/package availability rather than adding arbitrary third-party repositories.

8. AlmaLinux: XFCE + RDP

Inside AlmaLinux:

sudo dnf update -y
sudo dnf group list
sudo dnf search xfce

Install the available XFCE group/packages, then:

sudo dnf install xrdp -y
sudo systemctl enable --now xrdp
sudo firewall-cmd --permanent --add-port=3389/tcp
sudo firewall-cmd --reload
echo "startxfce4" > ~/.Xclients
chmod +x ~/.Xclients

9. Why keep both VNC and RDP?

The VNC configured by virt-install --graphics vnc is the QEMU virtual console, not a VNC server running inside the guest. It can show UEFI, GRUB, the installer, boot failures and recovery screens even when guest networking is broken.

RDP/xrdp is better for everyday XFCE desktop access after the guest has booted.

So a useful setup is:

Arch host
   │
QEMU/libvirt VNC console
   │
Guest VM (Ubuntu/Rocky/Alma)
   │
XFCE + xrdp
   │
br0 → 192.168.1.x → RDP

Keep QEMU VNC as the rescue console and use RDP for normal GUI access.

10. virsh management commands

List all VMs:

sudo virsh list --all

List running VMs:

sudo virsh list

Start:

sudo virsh start ubuntu

Normal/ACPI shutdown:

sudo virsh shutdown ubuntu

Restart:

sudo virsh reboot ubuntu

Force power off:

sudo virsh destroy ubuntu

destroy does not delete the VM. It is comparable to pulling the power cord.

Pause:

sudo virsh suspend ubuntu

Resume:

sudo virsh resume ubuntu

11. VM autostart

Enable:

sudo virsh autostart ubuntu

Check:

sudo virsh dominfo ubuntu | grep Autostart

Disable:

sudo virsh autostart ubuntu --disable

With an 8 GB host, avoid autostarting all three guests unless their workloads are very light.

12. Delete a VM

A VM consists of its libvirt definition plus its virtual disk/storage.

virsh undefine alone removes the definition but can leave the qcow2 disk behind.

First shut down:

sudo virsh shutdown ubuntu
sudo virsh list --all

Inspect its storage:

sudo virsh domblklist ubuntu

To remove a UEFI guest and its managed storage completely:

sudo virsh undefine ubuntu --remove-all-storage --nvram

Warning: --remove-all-storage is destructive and deletes the VM's storage.

Verify:

sudo virsh list --all
ls -lh /var/lib/libvirt/images/

Quick reference

Recommended addition: QEMU Guest Agent

Install qemu-guest-agent inside Ubuntu, Rocky and AlmaLinux. It allows libvirt to communicate more cleanly with the running guest and improves VM management from the host.