MC nodes are shipped from the factory running a specialized bootstrap OS. The latest version of the Azure Stack HCI payload is stored on the BOSS card of each MC node for automated Day 1 deployment and cluster configuration onsite. Dell ProDeploy Services provides a white-glove installation experience until the platform becomes customer-installable. ProDeploy technicians leverage the APEX Cloud Platform Foundation Software to provision the server operating system, update firmware and drivers, and configure the networking, storage, and cluster settings using an intuitive, guided user interface.
Storage Spaces Direct functions as the primary storage solution for Azure Stack HCI. It combines the internal drive performance and capacity across cluster nodes into a single resilient and highly performant software-defined pool of virtual shared storage. Cluster Shared Volumes (CSVs) enable multiple cluster nodes to simultaneously have read/write access to the same disk provisioned with the Resilient File System (ReFS), which is the file system purpose-built for virtualization. You can scale out the storage capacity and performance of your cluster by adding more drives or by adding more nodes to the cluster.
Storage Spaces Direct is a core technology of Azure Stack HCI and therefore cannot be disabled even if you intend to exclusively consume PowerFlex capacity for your workloads. The platform at least requires enough S2D capacity to host critical VMs like the Cloud Platform Manager and Azure Arc Resource Bridge. These VMs are created at initial Azure Stack HCI cluster creation and must remain on S2D CSVs for the life of the cluster. During testing, Dell Engineering found that Azure Stack HCI clusters needed a minimum of two disk drives in each cluster node to meet these requirements.
Azure Stack HCI clusters access the PowerFlex block storage through the Storage Data Client (SDC) installed on each cluster node. Azure Stack HCI cluster nodes require host networking changes to communicate with the PowerFlex cluster. There are also specific network infrastructure requirements that are covered in this guide and the implementation guide. After a PowerFlex volume is created in PowerFlex Manager and mapped to the Azure Stack HCI cluster nodes, the volumes appear as local block devices on every node. Then, a CSV formatted with the NTFS file system is created to unify all these volumes into a single namespace accessible through any server.