Metadata, from basic file names to multiprotocol ACLs and locks, is maintained on shared non-volatile media in VAST enclosures. This allows the mirrored and distributed metadata to serve as a consistent single source of truth. This approach delivers distinct advantages.
Enhanced Resilience: No DRAM write caching means zero volatility in the data path and no need to rebuild data when Servers fail. Data structures are always atomic eliminating the need for cache coherency.
Linear scale: Without the need for east-west cluster traffic every Server and Enclosure adds a proportionately linear amount of performance to the VAST Cluster.