QEMU on Fedora 39 for RHCSA Practice

Set up KVM/QEMU on Fedora 39 for RHCSA Practice.

1. First, verify that your CPU supports virtualization:

grep -E 'vmx|svm' /proc/cpuinfo

If you see output, your CPU supports virtualization.

2. Check if KVM modules are loaded:

lsmod | grep kvm

You should see kvm_intel (for Intel CPUs) or kvm_amd (for AMD CPUs).

3. Install the required packages:

sudo dnf groupinstall "Virtualization"
sudo dnf install bridge-utils libvirt virt-install virt-manager virt-viewer

4. Start and enable the libvirtd service:

sudo systemctl start libvirtd
sudo systemctl enable libvirtd

5. Add your user to the libvirt group:

sudo usermod -aG libvirt $USER
sudo usermod -aG kvm $USER

You’ll need to log out and back in for these changes to take effect.

6. Verify the installation:

virsh list --all

This should show an empty list of VMs without any errors.

7. Set up the default network:

sudo virsh net-start default
sudo virsh net-autostart default

8. Launch Virtual Machine Manager:

virt-manager

Basic network configurations will be automatically created, including:

• default NAT network (192.168.122.0/24)
• virbr0 bridge interface

Also, make sure to download a Rocky Linux or AlmaLinux ISO (these are free RHEL alternatives) if you want to start creating VMs for RHCSA practice.

next blog posts will be about :

1. Creating your first VM using virt-manager
2. Setting up additional networks for VM-to-VM communication

I notice both your VMs are using the same network (192.168.122.0/24) with br0 having the same IP (192.168.122.100) on both machines. Let’s set up distinct IP addresses and configure them properly.

Here’s how to configure different IP addresses for your VMs:

1. First, let’s modify the network configuration in VM1. Create/edit the network script:

sudo nmcli connection modify br0 ipv4.addresses 192.168.10.10/24
sudo nmcli connection modify br0 ipv4.gateway 192.168.10.1
sudo nmcli connection modify br0 ipv4.method manual
sudo nmcli connection up br0

2. For VM2, set a different IP address:

sudo nmcli connection modify br0 ipv4.addresses 192.168.10.20/24
sudo nmcli connection modify br0 ipv4.gateway 192.168.10.1
sudo nmcli connection modify br0 ipv4.method manual
sudo nmcli connection up br0

Alternatively, you can configure this using the traditional network configuration files:

For VM1 (/etc/sysconfig/network-scripts/ifcfg-br0):

TYPE=Bridge
BOOTPROTO=none
NAME=br0
DEVICE=br0
ONBOOT=yes
IPADDR=192.168.10.10
PREFIX=24
GATEWAY=192.168.10.1

For VM2 (/etc/sysconfig/network-scripts/ifcfg-br0):

TYPE=Bridge
BOOTPROTO=none
NAME=br0
DEVICE=br0
ONBOOT=yes
IPADDR=192.168.10.20
PREFIX=24
GATEWAY=192.168.10.1

After making these changes:

# Restart the network service
sudo systemctl restart NetworkManager
 
# Or bring the interface down and up
sudo nmcli connection down br0
sudo nmcli connection up br0

To verify connectivity:

# From VM1
ping 192.168.10.20
 
# From VM2
ping 192.168.10.10

If you want to create a completely separate network for practice:

1. Create a new bridge network in libvirt:

cat << EOF > bridge-network.xml
<network>
  <name>bridge10</name>
  <bridge name='br10'/>
  <forward mode='route'/>
  <ip address='192.168.10.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.10.100' end='192.168.10.200'/>
    </dhcp>
  </ip>
</network>
EOF
 
sudo virsh net-define bridge-network.xml
sudo virsh net-start bridge10
sudo virsh net-autostart bridge10

2. Then attach this new network to your VMs:

sudo virsh attach-interface --domain vm1 --type network --source bridge10 --model virtio --config --live
sudo virsh attach-interface --domain vm2 --type network --source bridge10 --model virtio --config --live