Smart active-active high availability DAS systems

摘要

A high availability DAS system using uses a solid state cache to provide near active-active performance in a DAS cluster, while retaining the implementation simplicity of active-passive or dual active system. Each node in the cluster may inlude a solid state cache that stores hot I/O in an active-active mode, which allows the data to be read from or written to the underlying dual-active or active/passive DAS RAID system only when access to the "hot Region" cools down or in the case of Cache Miss. The hot I/O data includes hot read data that accumulated dynamically regardless of ownership of the drives where the hot read data is permanently stored. The hot I/O data also includes hot write data that is mirrored across the solid state cache memories to avoid potential dirty write data conflicts and also to provide High Availability in case of server failures.