Product : StorPool, StorPool [SDS]/19.01, x86
Feature : Memory Purpose, Memory, Storage Support
Content Owner:  Herman Rutten
Read Cache
Write-back Cache (optional)
Memory is used by StorPool for storing metadata, read caching, and proprietary write back-caching (WBC).

When HDDs are used, write operations are usually processed through a write-back cache to reduce the write latency and sequence the write operations to maximize the performance of each disk drive. In typical deployments, this write-back cache is implemented with a persistent storage layer such as power-loss protected memory in RAID controllers or an Optane NVMe drive. This approach guarantees consistent data and data-loss protection in unlikely events such as simultaneous power loss of the entire site.

In non-critical deployments with lower requirements, the write-back cache can be configured to be stored in the DRAM. This can reduce the hardware cost by eliminating the RAID controller with power-loss protected memory or Optane NVMe drive.