Using Hybrid Storage Pools:
First Tier: DRAM (large L1 cache) – DRAM memory and high-optimized and low-latency solid state disks combined with ZFS file systems architecture (ReadZilla) accelerate read-cache operations for the virtualized environment. Unlike traditional NAS architecture, Oracle ZFS Storage Appliance and its Hybrid Storage Pools utilize DRAM devices as the main cache device of the system. DRAM devices are cheaper, faster and deliver higher performance than NVRAM, so they are well matched for random I/O workloads – the kind of workloads performed by hypervisors/virtualized environments. DRAM devices are also used by the Adaptive Replacement Cache (ARC), which is part of the ZFS file system architecture model and intelligently managed by instructions provided by multiple cache algorithms.