hesela.devMirror-accelerated parity
Mirror-accelerated parity is a ReFS volume arrangement that combines mirror and parity regions and rotates data from mirror to parity.
ReFS can write into mirror and later rotate data to parity; insufficient free mirror space can instead cause direct parity writes. At the ReFS tiering layer, reads do not themselves rotate parity data into mirror. Separate drive caching can still accelerate reads. [1] [2]
Mirror and parity identify resiliency, not necessarily SSD and HDD media. This arrangement requires ReFS but is not exclusive to Storage Spaces Direct: the standalone Storage Bus Cache tutorial also describes operation with ReFS volumes on Windows Server 2022. [3] [4]
In the standalone tutorial's resilient setup, the bus cache serves reads; the mirror tier provides write caching with the default Shared provision mode. This is different from the read/write bus cache described for non-resilient Simple spaces. [4]
Relations
- related
- Storage Spaces, Storage Spaces Direct, ReFS, Mirroring (storage), Parity RAID, Storage Bus Cache
Citations
- Microsoft Learn: Mirror-accelerated parity rotation and I/O behavior
- Microsoft Learn: Storage pool cache at the drive layer
- Microsoft Learn: Create volumes: mirror-accelerated parity requires ReFS
- Microsoft Learn: Standalone Storage Bus Cache prerequisites and ReFS volumes
Sources & caveats
- Documentation synthesis, not an executed Windows experiment or a performance guarantee. The standalone tutorial's explicit prerequisites are narrower than its general version banner.