Patent ID: 7493617
Filing Date: 2009-02-17
Classification: G06F

Abstract:
1. A method for copying data, comprising: initiating transfer of at least one group of data units from a primary storage system to a secondary storage system, said group of data units having a plurality of data units that are to be transferred; defining a respective task for monitoring a progress of the transfer of each of the respective data units; and maintaining a plurality of states for monitoring a progress of the transfer of said plurality of data units in the at least one group, said plurality of states comprising at least a normal state indicating that a data unit in the plurality of data units is ready to be transmitted, a recovery state to which a task associated with a data unit transitions if the data unit had a recoverable failure but is not yet ready to retry, a retry state to which the task associated with a data unit transitions when status of all other data units in the plurality of data units is ascertained, and a failed state to which the task associated with a data unit transitions if the data unit had an unrecoverable failure; wherein the states allow for error recovery of sending multiple data units; wherein each of the units of data comprises a track of data; the transfer of at least one group comprises a multi-track transfer; wherein transfer of a plurality of groups of data units from the primary storage system to the secondary storage system is initiated; a respective task is defined for monitoring a process of the transfer of each of the respective data units in the plurality of groups; a state is maintained for monitoring a process of the transfer of each of the groups; for each of the groups, the state thereof is responsive to the process of each of the tasks thereof; and maintaining data associating each of the tasks with its associated group.