Creating instances that use the Compute Engine virtual network interface

The Compute Engine virtual network interface (also known as gVNIC) is specifically designed for use on Compute Engine. Compute Engine virtual network interface provides a more efficient delivery network for sending traffic to and from your VM instances. Previously, virtual machine (VM) instances that run on Compute Engine use a virtual network interface based on the virtIO specification.

The Compute Engine virtual network interface is required to support higher network bandwidths such as the 50-100 Gbps speeds that can be used for distributed workloads on instances that have attached GPUs.

To create VM instances that use the Compute Engine virtual network interface, you can complete one of the following steps:

Create your VM instances using an image from the gvnic-vm-image-prod image family.
Manually install the Compute Engine virtual network driver on any Linux image of your choice and then use the image to create a VM instance.

Before you begin

If you want to use the command-line examples in this guide:
1. Install or update to the latest version of the gcloud command-line tool.
2. Set a default region and zone.
If you want to use the API examples in this guide, set up API access.

Limitations

The Compute Engine virtual network interface is not supported on VM instances that use memory-optimized machine types.

Operating system support

The following images belong to the gvnic-vm-image-prod image project and are configured to use the Compute Engine virtual network interface:

Debian 9 - debian-9-gvnic
Windows
- Windows Server 2019 - windows-2019-gvnic
- Windows Server 2016 - windows-2016-gvnic
- Windows Server 2012 R2 - windows-2012-r2-gvnic

You can use any of these images to create a VM instance that, by default, uses the Compute Engine virtual network interface.

Creating a VM instance using pre-configured images

To create a VM instance using an image from the gvnic-vm-image-prod image project, follow the steps to create a VM instance and provide the image project and image family.

Debian

To create a Debian instance, run the following command:

gcloud beta compute instances create instance-name \
      --image-project=gvnic-vm-image-prod \
      --image-family=debian-9-gvnic

Replace instance-name with the name of your instance.

Windows

To create a Windows 2019 instance, run the following command:

gcloud beta compute instances create instance-name \
        --image-project=gvnic-vm-image-prod \
        --image-family=windows-2019-gvnic

To create a Windows 2016 instance, run the following command:

gcloud beta compute instances create instance-name \
          --image-project=gvnic-vm-image-prod \
          --image-family=windows-2016-gvnic

To create a Windows 2012-r2 instance, run the following command:

gcloud beta compute instances create instance-name \
          --image-project=gvnic-vm-image-prod \
          --image-family=windows-2012-r2-gvnic

Replace instance-name with the name of your instance.

Manually installing the Compute Engine virtual network driver

To create a VM instance from an image that does not have the Compute Engine virtual network driver installed, you need to:

Install the Compute Engine virtual network driver on the image.
Use the image, that now has the Compute Engine virtual network driver installed, to create a VM instance.

Linux

Before you can install the Compute Engine virtual network driver, you must install the latest versions of the kernel driver and header for your operating system. An instance that uses a Compute Engine virtual network interface without a kernel driver will not have internal or external network connectivity, including SSH and RDP.

To build and install the kernel driver from source you must have a supported kernel with headers installed. The Compute Engine virtual network driver supports building against mainline and major distribution kernels for versions 3.10 and later.

Install or update kernel and headers to version 3.10 or later. To complete this step, review the documentation for your operating system. Source code and driver packages can be obtained from GitHub, see GoogleCloudPlatform/compute-virtual-ethernet-linux.
Use your image to create and start a VM instance.
On this VM instance, load the kernel driver. To load the driver run the following command:
```
modprobe gve
```
This command loads the driver until you either reboot the system or remove the driver with the rmmodcommand.
(Optional) To ensure that the driver loads automatically when the system boots, run one of the following commands:
- For operating systems that use systemd, run the following command:
```
echo gve > /etc/modules-load.d/gve.conf
```
- For Debian systems, run the following command:
```
echo gve >> /etc/modules
```
Stop the VM instance.
Create an image from the disk that is attached to the VM instance that you just stopped.
```
gcloud beta compute images create image-name\
        --source-disk disk-name \
        --guest-os-features=GVNIC
```
Replace the following:
- image-name: The name of the image that you want to create. This image has the Compute Engine virtual network driver installed.
- disk-name: The name of the boot disk on the VM instance that you just stopped.
Use the image, which has the Compute Engine virtual network driver installed, to create and start a VM instance.

Windows

Use your image to create and start a VM instance.
On this VM instance, install GooGet. To install GooGet, see Download and install GooGet.
Install the gVNIC driver. To install the driver, run the following command in an elevated PowerShell prompt:
```
googet install google-compute-engine-driver-gvnic
```
Stop the VM instance.
Create an image from the disk that is attached to the VM instance that you just stopped.
```
gcloud beta compute images create image-name\
        --source-disk disk-name \
        --guest-os-features=GVNIC
```
Replace the following:
- image-name: The name of the image that you want to create. This image now has the Compute Engine virtual network driver installed.
- disk-name: The name of the boot disk on the VM instance that you just stopped.
Use the image, which has the Compute Engine virtual network driver installed, to create and start a VM instance.

Verifying that the Compute Engine virtual network interface is enabled

Linux

Method 1

On your Linux VM instance, run the following commands:
```
sudo apt install pciutils
lspci
```
The output should resemble the following:
```
00:04.0 Ethernet controller: Google, XXX. Device 0042
```

Method 2

Follow the instruction for your operating system to download the ethtool networking utility tool.

Run the following command:

sudo ethtool -i network-interface

Replace network-interface with the name of your network interface. For example, eth0.

The output should resemble the following:

driver: gve
version: 1.0.0
firmware-version:
expansion-rom-version:
bus-info: 0000:00:04.0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no

Windows

On your Windows VM Instance, open the Device Manager.
Under Network Adapters, you should see: "Google Ethernet Adapter"

Troubleshooting

VM instance didn't boot

Cause: Compute Engine virtual network driver is not enabled on the image.
Diagnosis: Check that the image has Compute Engine virtual network interface enabled. To verify, run the following command:
```
gcloud beta compute images describe image-name
```
Replace image-name with the name of your image.

The output of the command should show 'GVNIC' under guestOsFeatures.
Resolution: Ensure that you are using a supported image or that you have properly set up the gVNIC driver on your custom image.

VM instance booted but is not reachable over the network

Cause: The Compute Engine virtual network driver was not successfully installed and loaded.
Diagnosis: To check if the driver was installed and loaded, complete the following steps:
Linux
1. Check that the driver is installed.
```
modinfo gve
```
  The output should resemble the following:
```
filename:       /lib/modules/4.15.0-1036-gcp/updates/dkms/gve.ko
version:        1.0.0
license:        Dual MIT/GPL
description:    gVNIC Driver
author:         Google, XXX.
srcversion:     5FEFB9DD945EB2DEC94EE09
alias:          pci:v00001AE0d00000042sv*sd*bc*sc*i*
depends:
retpoline:      Y
name:           gve
vermagic:       4.15.0-1036-gcp SMP mod_unload
```
2. Check that the driver is loaded.
```
lsmod | grep gve
```
  The output should resemble the following:
```
gve                    49152  0
```
Windows
1. Connect to instance through SAC.
2. Login with your username and password.
3. From the command prompt, run the following command:
```
dism /online /get-drivers | findstr gvnic
```
4. Review the result.
  - If the driver is installed, you should see the text Original File Name : gvnic.inf in the output.
  - If the driver is not installed, no message is returned.
Note: You can also review the interactive serial console when debugging issues with your connection.
Resolution: If the Compute Engine virtual network driver is not available, ensure that you are using a supported image or that you have properly set up the Compute Engine virtual network driver on your custom image.

What's next

Connect to your instance.
Add persistent disks to your new instance.