Hardware and Network Requirements

As an HCI solution on bare metal servers, there are minimum node hardware and network requirements for installing and running Harvester.

A three-node cluster is required to fully realize the multi-node features of Harvester. The first node that is added to the cluster is by default the management node. When the cluster has three or more nodes, the two nodes added after the first are automatically promoted to management nodes to form a high availability (HA) cluster.

Certain versions of Harvester support the deployment of single-node clusters. Such clusters do not support high availability, multiple replicas, and live migration.

Hardware Requirements

Harvester nodes have the following hardware requirements and recommendations for installation and testing.

important

• For best results, use YES-certified hardware for SUSE Linux Enterprise Server (SLES) 15 SP3 or SP4. Harvester is built on SLE technology and YES-certified hardware has additional validation of driver and system board compatibility. Laptops and nested virtualization are not supported.
• Each node must have a unique product_uuid (fetched from /sys/class/dmi/id/product_uuid) to prevent errors from occurring during VM live migration and other operations. For more information, see Issue #4025.
• Harvester has a built-in management cluster network (mgmt). To achieve high availability and the best performance in production environments, use at least two NICs in each node to set up a bonded NIC for the management network (see step 6 in ISO Installation). You can also create custom cluster networks for VM workloads. Each custom cluster network requires at least two additional NICs to set up a bonded NIC in every involved node of the Harvester cluster. The witness node does not require additional NICs. For more information, see Cluster Network.
• During testing, you can use only one NIC for the built-in management cluster network (mgmt), and for testing the VM network that is also carried by mgmt. High availability and optimal performance are not guaranteed.

CPU Specifications

Live Migration functions correctly only if the CPUs of all physical servers in the Harvester cluster have the same specifications. This requirement applies to all operations that rely on Live Migration functionality, such as automatic VM migration when Maintenance Mode is enabled.

Newer CPUs (even those from the same vendor, generation, and family) can have varying capabilities that may be exposed to VM operating systems. To ensure VM stability, Live Migration checks if the CPU capabilities are consistent, and blocks migration attempts when the source and destination are incompatible.

When creating clusters, adding more hosts to a cluster, and replacing hosts, always use CPUs with the same specifications to prevent operational constraints.

Network Requirements

Harvester nodes have the following network requirements for installation.

Port Requirements for Harvester Nodes

Harvester nodes require the following port connections or inbound rules. Typically, all outbound traffic is allowed.

Port Requirements for Integrating Harvester with Rancher

If you want to integrate Harvester with Rancher, you need to make sure that all Harvester nodes can connect to TCP port 443 of the Rancher load balancer.

When provisioning VMs with Kubernetes clusters from Rancher into Harvester, you need to be able to connect to TCP port 443 of the Rancher load balancer. Otherwise, the cluster won’t be manageable by Rancher. For more information, refer to Rancher Architecture.

Port Requirements for K3s or RKE/RKE2 Clusters

For the port requirements for guest clusters deployed inside Harvester VMs, refer to the following links:

• K3s Networking
• RKE Ports
• RKE2 Networking