hesela.devStorage Spaces Direct
Storage Spaces Direct combines server-local drives into clustered software-defined storage using Storage Spaces and Windows clustering.
The architecture combines clustering, SMB communication, a Software Storage Bus and shared-volume access. It is not another name for ReFS or for a standalone storage pool. [1]
Its server-side pool cache operates at the drive layer, below volume resiliency. Cache-device selection and read/write behavior depend on the drive configuration; homogeneous drive types do not automatically create dedicated cache drives. This cache is separate from ReFS mirror-to-parity rotation. [2]
When a cache is configured, flash capacity uses write-only caching by default; HDD capacity uses read/write caching. Reads of newly written, undestaged data can still come from a write-only cache. Cache drives do not add usable cluster capacity. Cache persistence is not another replica: recovery after a cache-drive failure relies on surviving copies elsewhere. [2]
Relations
- related
- Storage Spaces, Mirror-accelerated parity, ReFS, SMB file sharing, Failure domain, Storage Bus Cache
Citations
- Microsoft Learn: Storage Spaces Direct architecture
- Microsoft Learn: Storage pool cache at the drive layer
Sources & caveats
- Describes the documented clustered architecture, not a claim that every Windows edition or hardware configuration supports it. No cluster was deployed or benchmarked.