Microsoft Storage Spaces Write-Back Cache exists on HDD-only single-tier parity disk?
As per Microsoft documentation for parity Pools default 32MB cache will be always created. https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/dn387076%28v%3dws.11%29 However, I've never found which media WBC is using, I assume it will use RAM for cache. Unfortunately, you can't change this value after the space was created.