Dell EMC Solutions for Microsoft Azure Stack HCI requires a reliable, high bandwidth, low latency network connection between each clustered node for storage network traffic. Dell Technologies recommends using redundant 10 Gb/s / 25 Gb/s / 100 Gb/s 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:
- Data center environments with an existing 1 GbE network switch infrastructure reduce costs that are associated with upgrading to 10 GbE (or faster) switches, since 10 GbE is a storage network minimum requirement of Storage Spaces Direct.
- Data center environments with an existing 10 GbE network switch infrastructure would gain increased network throughput for storage traffic, since there are 25 GbE network adapter connections between each clustered node.
Note: 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 Technologies recommends that expansion for switchless clusters be redeployed from scratch in order to properly follow cabling procedures and prevent any operating system misconfiguration.