To support the SAP HANA bandwidth requirements, Dell EMC recommends configuring the VxRail nodes with two 25 GbE SFP28 network daughter cards (NDCs) and an additional two 25 GbE SFP28 connectivity cards for SAP HANA application network traffic—the SAP HANA internode. While 10 GbE network configurations are also supported, these configurations provide limited network and storage performance, which might result in longer SAP HANA database restart times and a smaller number of SAP HANA VMs that can be supported in the cluster.
With more than two SAP HANA VMs on any VxRail node, a 25 GbE network for vSAN is required to meet the SAP storage performance requirements.
Besides the system networks that are required for vSphere and vSAN software, configure the following networks for SAP HANA including system replication if the corresponding function (SAP HANA system replication) is used:
Create a new vSphere distributed switch (VDS) for the networks that are required for SAP HANA and assign the additional 2 x 25 GbE (or 2 x 10 GbE) network cards as uplinks to this new distributed switch. To meet the performance requirements of the SAP HANA internode network communication, set an MTU size of 9,000 on the distributed switch and in the operating system network settings of the SAP HANA VM for the internode network. Follow VMware and SAP HANA requirements and best practices when configuring networks on the VxRail distributed switch.
For detailed information about planning logical and physical VxRail networks, see the Dell EMC VxRail Network Planning Guide.