Patent ID: 7827362

Claim:
A storage management device for accessing at least one logical unit, comprising: a plurality of input/output (I/O) processing modules, comprising: a host interface in communication with a host for receiving I/O requests, and extracting a plurality of ordered operation commands associated with each I/O request, including an identification operation command and other operation commands, the plurality of ordered operation commands processed to execute the I/O request, wherein at least one of the I/O requests incurs a copy-on-write operation; an I/O manager in communication with the host interfaces of the I/O processing modules, the I/O manager for processing the extracted operation commands first using a logical unit number (LUN) queue and thereafter using one or more operation-type queues, wherein an identification operation command in the plurality of ordered operation commands is stored in the LUN queue, and the other operation commands are stored in one or more of the one or more operation-type queues, and wherein each of the one or more operation-type queues stores operation commands of a single specific operation type; and a physical store interface in communication with the I/O managers of the I/O processing modules, the physical store interface for communicating with at least one logical unit in response to the processed operation commands; and an internal network for communication among the I/O processing modules.