Multi-node cache coherency with input output virtualization

Abstract

Systems and methods maintain cache coherency between storage controllers using input/output virtualization. In one embodiment, a primary storage controller receives write commands over a virtualized interface, stores the write commands in cache memory, tracks a status of the write commands processed from the cache memory, and stores the status in a portion of the cache memory. A backup storage controller includes a backup cache that receives replications of the write commands via direct memory access operations, and stores the replications of the write commands. The primary storage controller makes the status available to a host system. In response to a failure of the primary storage controller, the backup storage synchronizes with the status from the host system, and resumes I/O operations for the logical volume.