Patent ID: 8332549

Claim:
A method for communication between an initiator system and a block storage cluster, comprising: receiving a first input/output (I/O) request from the initiator system, the first I/O request associating data for transfer to or transfer from a storage location; sending an immediate referral response from a first storage system included in a plurality of storage systems of the block storage cluster to the initiator system when data associated with the first I/O request is stored in more than one storage system of the plurality of storage systems of the block storage cluster, the immediate referral response providing information for directing the initiator system to a second storage system storing data associated with the first I/O request, the second storage system included in the plurality of storage systems of the block storage cluster; directing a referral I/O request to the first storage system and the second storage system for transferring data to or transferring data from the first storage system and the second storage system; transferring data associated with the referral I/O request to or transferring data associated with the referral I/O request from the first storage system and the second storage system; directing in parallel a plurality of sets of referral I/O request operations to the plurality of storage systems of the block storage cluster based upon the immediate referral response for transferring data to or transferring data from the plurality of storage systems of the block storage cluster; and transferring data associated with the plurality of sets of referral I/O requests to or transferring data associated with the plurality of sets of referral I/O requests from the plurality of storage systems of the block storage cluster, wherein the immediate referral response includes a check condition from the first storage system included in the plurality of storage systems of the block storage cluster to the initiator in response to the first I/O request when data associated with the first I/O request is stored in more than one storage system of the plurality of storage systems of the block storage cluster, the check condition including sense data which contains a list of ports where data associated with the first I/O request resides.