Home > Workload Solutions > SQL Server > White Papers > Scaling SQL Server 2022 VMs on Dell Integrated System for Microsoft Azure Stack HCI > Storage layer architecture
Each node is crucial and contributes to both storage and compute functions for HCI deployments. In environments where I/O intensive applications such as SQL Server are deployed, the underlying storage layer plays a vital role. Storage Spaces Direct is a core technology of Azure Stack HCI that enables users to pool and consolidate all hard drives across nodes into a software-defined solution.
Storage Spaces Direct uses the Software Storage Bus to dynamically bind the fastest drives available in the pool to slower drives hence enhancing overall IO and throughput. Microsoft strongly recommends customers use one pool per cluster. It is automatically created, and all eligible drives are added to it. To learn more about Microsoft’s recommendations, see Storage Spaces Direct overview.
The physical drives used in this solution were configured into a single pool. To access this pool, we created parity and mirrored Cluster Shared Volumes (CSVs) based on throughput and availability requirements. On these CSVs, we placed the Virtual Hard Disks (.vhds) which were connected to each VM across multiple SCSI controllers. The volume and controller layout for our pool is described in Figure 8.