Patent ID: 7650385

Claim:
A method for assigning priorities, comprising: under control of a primary control unit, receiving a request to manipulate data; determining a type of the request, wherein the type of the request includes a synchronous copy command, an asynchronous copy command, and an establish with copy command; assigning a priority to the request based on the type of the request by: assigning the request a high priority when the type of the request is the synchronous copy command and a host has not assigned a priority to the request; assigning the request a medium priority when the type of the request is the asynchronous copy command; and assigning the request a low priority when the type of the request is the establish with copy command; and sending a command to a secondary control unit, wherein the command includes the request and the assigned priority, wherein the primary control unit and the secondary control unit allocate resources to handle the request based on the assigned priority; and under control of the secondary control unit, using the priority assigned to the request by the primary control unit to process the request.