Microsoft recommends using mirroring for most performance-sensitive workloads. We followed that guidance for the VMS and CV testing we describe later in this paper. For large clusters with a mixture of performance-sensitive workloads, Storage Spaces Direct with Azure Stack HCI allows administrators to create volumes using different levels of data protection including three-way mirroring and several options for mirror-accelerated parity.
Mirror-accelerated parity (MAP) reduces the footprint of the volumes in the storage pool. For example, a three-way mirror volume would use 30 TB in the pool for every 10 TB of volume size. To reduce the overhead in footprint, create a volume with mirror-accelerated parity. Using MAP reduces the footprint from 30 TB to 22 TB when using only four servers, mirroring the most active 20 percent of data and using more space-efficient parity to store the rest. Storage Spaces Direct gives users a range of ratio options of parity and mirrors to match the performance compared with the capacity tradeoff for a range of workloads.