Patent ID: 7472231

Claim:
A storage area network comprising: a virtualization engine; a first network port connected to said virtualization engine to receive data access requests from one or more hosts, said data access requests identifying data with virtual addresses; a second network port connected to said virtualization engine to connect to a plurality of storage controllers, said virtualization engine to translate the virtual addresses into physical addresses and to forward the data access requests to one or more storage controllers of the plurality of storage controllers according to the physical addresses; a data cache connected to and directly accessible by said virtualization engine with the virtual addresses using a segment identifier for identifying at least one segment combined with a block identifier for identifying at least one block of the identified segment to be accessed, said data cache further including: a first level look-up table providing a first hit signal and a segment structure address if the segment identifier corresponds to a segment in said data cache; and a second level look-up table having a control structure memory providing a final hit signal and a storage address if a block being accessed corresponds to a block in said data cache wherein the control structure further includes status information bits: write in progress, read in process, data valid, dirty and flush in progress bits.