Storage Spaces offers simple spaces, mirror spaces, and parity spaces, each with unique characteristics.
- Simple spaces are designed for increased performance when resiliency isn't very important. They are best suited for temporary data, such as video rendering files, image editor scratch files, and intermediary compiler object files. Simple spaces require a minimum of one physical disk.
- Mirror spaces are designed for increased performance and increased resiliency. Two-way mirror spaces can tolerate one disk failure and three-way mirror spaces can tolerate two disk failures. They are well suited to storing a broad range of data, from a general-purpose file share to a VHD library. When a mirror space is formatted with the Resilient File System (ReFS), Windows offers automatic data integrity maintenance. This is a layer of resiliency is above and beyond the resiliency achieved from maintaining multiple data copies to tolerate drive failure.
Mirror spaces require at least two disks (per tier if you use storage tiers) to protect you from a single disk failure. To protect a virtual disk from two simultaneous disk failures, you need at least three disks (per tier), with a minimum of five disks total in the pool to maintain pool metadata.
- Parity spaces are designed for capacity efficiency and increased resiliency. Parity spaces are best suited for archival data and streaming media, such as music and videos. This storage layout requires at least three disks to protect you from a single disk failure and at least seven disks to protect you from two disk failures.