Note: This section is only relevant if you are planning to deploy a VxRail cluster with vSAN using RoCE-compliant Ethernet adapters.

If the VxRail nodes targeted for deployment are configured with Ethernet adapters that support RDMA over Converged Ethernet (RoCE), the switches and supporting network need to be configured to enable a “lossless” network for the vSAN traffic.

Converting a cluster to enable RoCE on the vSAN datastore is performed after the VxRail initial build. Consult the technical reference guides from your switch vendor for the specific steps to configure on the physical network. The basic step to ensure a “lossless” network are as follows:

• vSAN with RDMA supports NIC failover, but does not support link aggregation or NIC teaming based on IP hash.
• Data Center Bridging must be enabled on the switches supporting the VxRail cluster
• Control traffic flow on the switches using a mechanism such as Priority Flow Control (PFC). Set the RoCE network to a higher priority as outlined in your vendor documentation.
• Configure RoCE on vSAN on a priority-enabled VLAN
• If the vSAN traffic will be on a routed Layer 3 network, the “lossless” network settings must be preserved when routed across network devices using a feature such as the Differentiated Service Code Point (DSCP) QoS setting.