EMC VNX – RAID groups vs Storage Pools With EMC training I have learnt some general guidelines, that should be followed to optimize and enable good performance on a VNX Unified storage system. Drive types When you chose a specific drive type, you should base your choice upon the expected workload. FLASH – Extreme Performance Tier – great for extreme performance. SAS – Performance Tier – perfect for general performance. Usually 10k RPM or 15k RPM. NL-SAS – Capacity Tier – most cos...