load overflow proxmox and elastic metal

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How to deal with load overflow between a proxmox cluster and virtual machines on an Elastic Metal Server over Scaleway Private Networks?

Reviewed on 22 November 2021Published on 20 May 2019
  • load-balancer
  • private-network
  • public-gateway
  • proxmox
  • virtual-machine


The Private Network feature enables you to build a virtual L2 network between your cloud resources. The service is compatible with a wide range of resources including:

In this tutorial we are going to create a Proxmox VE cluster. We want to be able to create several VMs on each Elastic Metal server, which will communicate over a Private Network. For this, a bridge is required. Bridges are like physical network switches implemented in software. We will create a bridge on each Elastic Metal server using the Proxmox interface. Once the bridge is created, we create a cluster and configure it to use the Private Network bridge as the cluster network. Each Elastic Metal server then joins this cluster. Next, we can create virtual machines on both servers of the cluster, which will communicate using the Private Network. Finally we can add and configure a Load Balancer to distribute traffic between all the VMs on the cluster.


Preparing Proxmox

  1. Log into the Proxmox web interface and select your server in the datacenter view. Then click Network in the menu.

  2. Click Create > Linux Bridge. The configuration wizard displays. Enter a private IP for your Elastic Metal server in CIDR format. The Bridge port is the name of your primary network interface, followed by a dot and your VLAN-ID. Tick the boxes Autostart and VLAN aware, then click Create to create the bridge.

  3. Click Apply configuration to activate the new configuration.

  4. Go to the Datacenter view and click Create Cluster.

  5. Enter a name for the cluster and select your Private Network bridge vmbr1 as cluster network. Then click Create to launch cluster creation.

  6. Select the cluster in the cluster list and click Join Information. The cluster join information displays.

  7. Click Copy Information to copy the cluster join information into the clipboard.

  8. Go to the Proxmox interface of your second Elastic Metal server and click Cluster to enter the cluster configuration from the Datacenter view of the machine.

  9. Click Join Cluster and paste the cluster join information in the form.

  10. Enter your first Elastic Metal server’s root password and click Join to link the machine to the cluster.

The second node appears now in the cluster in the Datacenter view of Proxmox. You can manage both machines using a single interface. Communication between members of the cluster is entirely via your Private Network, ensuring the highest level of security and the lowest latency.

Creating Virtual Machines

Proxmox is capable of managing Linux Kernel Virtual Machines (KVM) as well as LXC containers. KVM provides full virtualization for complete Windows and Linux images whilst LXC containers are lightweight and perfect to run conflict-free Linux applications. Follow this guide for information how to configure virtual machines and LXC containers on Proxmox.

Create or clone your virtual machines on both servers of the cluster to distribute the load between them using a Load Balancer. Your virtual machines can use the Public Gateway and dynamic NAT to communicate with the Internet for downloads and updates. If you want to expose certain ports of your VMs directly, configure static NAT rules) for them.


Make sure to select the bridge vmbr1, automatic MAC address generation and select DHCP for LXC network configuration.

The DCHP server in your Private Network will automatically assign a random IP address to your container or VM. If required, you can configure static NAT to assign a static IP address to it.

Configuring the Load Balancer

  1. Go to the Load Balancers section in the Scaleway console and select the Load Balancer you want configure.

  2. Click the Frontends tab, then + Add Frontend. The frontend configuration wizard displays.

  3. Enter the following information:

    For the frontend:

  • A name

  • The frontend port

  • (Optionally) The SSL certificate to use for the frontend

    For the backend:

  • A name

  • The backend protocol

  • The backend port

  • (Optionally) The proxy protocol to use

  • The healh check information

  • The IP addreses of your VM’s inside the Private Network


    For more information about the front and backend configuration, refer to the Load Balancers documentation.