Ensuring Data Consistency for High Available Storage Feature on Distantly-Multiple Storage Devices

This study proposes “Ticket method” for a remote copy system in 100km distance multi-site environment to avoid data corruption caused by process and communication overtaking. The method notifies failure event occurred in a primary storage device to a secondary storage device using ticket information. Increase of latency and table size for applying Ticket method is little. As a result of evaluation and comparison with traditional Sequence Number method, it was found latency time of Ticket method is 1/3 as that of Sequence Number method.