Patent ID: 8473648

Claim:
A method for I/O path virtualization between a RAID controller and an environment service module (ESM) in a storage area network (SAN), comprising: identifying a type of I/O request by an input/output (I/O) control engine upon receiving an I/O request from a host computer via a RAID controller; assigning a priority to the received I/O request based on the type of I/O request by the I/O control engine; interrupting processing of the prioritized I/O request by the I/O control engine, wherein interrupting the processing of the prioritized I/O request comprises: determining whether a host I/O time out value associated with the received I/O request is close to a predefined host I/O time out threshold value by the I/O control engine; if so, sending the prioritized I/O request to an associated disk drive in a drive tray via a plurality of solid state drive (SSD) buffer queues (SBQs) for execution by the I/O control engine; and if not, interrupting processing of the prioritized I/O request by the I/O control engine; separating the prioritized I/O request into a command I/O request or a status request; and sending the separated command I/O request or the status request to an associated queue in the plurality of SBQs in the I/O control engine.