Patent ID: 7934027

Claim:
A method of managing critical resource usage in a storage network comprising: monitoring a queue depth for a critical resource having a maximum queue depth; receiving an I/O (input/output) operation from a host for the critical resource; executing the I/O operation when the queue depth is below a threshold; calculating a new maximum queue depth for the critical resource when the queue depth for the critical resource exceeds the threshold; receiving a subsequent I/O operation from the host for the critical resource; placing the subsequent I/O operation in a waiting queue; blocking the subsequent I/O operation when the waiting queue has a queue depth that exceeds the new maximum queue depth; transmitting the new maximum queue depth to a peer storage controller; receiving, in the peer storage controller, an I/O operation from the host that identifies a storage unit; and processing the I/O operation using the new maximum queue depth, wherein the new maximum queue depth is calculated by dividing a number of available resources by a number of initiators waiting for the resources.