SYSTEMS AND METHODS FOR OBTAINING ULTRA-HIGH DATA AVAILABILITY AND GEOGRAPHIC DISASTER TOLERANCE

摘要

Network data storage systems and methods allow computers reading and writing data at a plurality of data centers separated by, potentially, large distances to replicate data between sites such that the data is protected from failures, including complete Site failures, while not allowing network latency to significantly impede the performance of read or wπte operations. Continued access to all data is provided even after a single failure of any component of the system or after any complete failure of all equipment regardless of geographic location. Wπte data is replicated synchronously from Active Sites, e g., sites where servers are wπting data to storage resources, to Protection Sites located sufficiently close to Active Sites such that network latency will not significantly impact performance, but sufficiently far apart such that a regional disaster is unlikely to affect both sites. Write data is then asynchronously copied to Active Sites, possibly at distant sites.