How to configure a Windows VM network adapter to use VirtIO

Written By Mircea Stoinescu (Internal Viewer)

Updated at June 2nd, 2025

→ Applies to: Hyperion 9.x and above

Network performance is essential to maintaining responsive virtual machines on Syneto Hyperion. By default, Windows VMs can use emulated network models such as e1000 or rtl8139, which favor compatibility over speed.

For better performance, these should be replaced with VirtIO (virtio-net), a paravirtualized interface that offers higher throughput and lower CPU usage.

VirtIO improves efficiency under heavy network loads, making it ideal for backups, high-traffic services, and latency-sensitive workloads.

To make the change, switch the model type from an emulated device to VirtIO. If the VirtIO drivers are not already installed, it is recommended to add a second temporary VirtIO interface to safely install the drivers. Without the driver, the VirtIO network device will not function.

Step 1. Shut down all VMs on the system

Step 2. Connect to SynetoOS appliance via SSH as admin

ssh admin@<your_ip_address_or_hostname>

Step 3. Become Super User

sudo su

Step 4. Edit manually a virtual machine (replace <vm-name> with the correct information)

virsh edit <vm-name>

Step 5. Change the network interface type to VirtIO

<interface type='network'>
  <mac address='52:54:00:e6:ce:57'/>
  <source network='default' portid='0f5f2058-cd34-4ab9-8050-22a0b85b4fcb' bridge='virbr0'/>
  <target dev='vnet1'/>
  <model type='e1000e'/>
  <link state='up'/>
  <alias name='net0'/>
  <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
</interface>

Keep the MAC address and source network as they are

Set model type='virtio'

Remove the target, link, alias, and address lines
<interface type='network'>
  <mac address='52:54:00:e6:ce:57'/>
  <source network='default'/>
  <model type='virtio'/>
</interface>
IMPORTANT

If the address line is not removed, the change may fail or cause incorrect configuration at runtime.

Step 6. Save the file and exit

ESC

:wq!

Step 7. Power on VM on the system

Step 8 (optional). Login to Windows VM and open device manager

Check that the network adapter is installed correctly

If the VirtIO drivers are already installed in Windows, the network interface should activate immediately. Otherwise, proceed with the driver installation.

To confirm that the VirtIO driver is in use for the network adapter, open Device Manager, expand the Network adapters section, and verify that the Red Hat VirtIO Ethernet Adapter is listed (as shown in the image above).

If Windows prompts for a new network path after the switch, you may need to reconfigure your firewall profile or network settings.

Syneto Knowledge

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