1. DB2 Data Sharing allows applications running on multiple DB2 subsystems to concurrently read and write to the same data, providing high scalability, performance, and continuous availability. 2. It provides benefits like increased capacity, continuous availability during planned and unplanned outages, easier growth accommodation, and dynamic workload balancing. 3. The Parallel Sysplex and Data Sharing architecture, along with features like rolling maintenance and dynamic workload balancing, work to ensure continuous availability even if a DB2 subsystem or z/OS system fails.