Azure Stack HCI requires a reliable, high bandwidth, low latency network connection between each clustered node for storage network traffic. Dell EMC recommends using redundant 10Gbps/25Gbps/100Gbps top-of-rack network switches for storage network traffic. Dell EMC PowerSwitch Data Center Switches offer a flexible, easy to deploy, cost effective network solution that is best for Microsoft Storage Spaces Direct and Failover Clustering. However, Microsoft announced support for 2-node switchless clusters for Windows Server 2019 Azure Stack HCI and Failover Clustering. Most recently, Microsoft has extended this support three and four node clusters, using a full mesh storage network topology. A full mesh interconnect requires direct network cable connections between every node of the cluster. These direct connections can be configured either using single or dual-link full mesh topologies. For redundancy and performance purposes, dual-link direct network connections between every node of the cluster are recommended.
Advantages of a full mesh switchless Storage Spaces Direct cluster:
Cluster size should be taken into careful consideration before deploying a full mesh switchless Storage Spaces Direct cluster. While possible, expanding a switchless cluster with an additional node may require additional network adapter cards to be installed. Creating the additional networks within Windows Server 2019 while the cluster remains running is not advised and the PowerShell scripts in this document are not designed for expansion purposes. Dell EMC recommends that expansion for switchless clusters be re-deployed from scratch in order to properly follow cabling procedures and prevent any OS misconfiguration.