Patent ID: 6487645
Filing Date: 2002-11-26
Classification: G06F,Y10S

Abstract:
A method for managing updates received at a primary data storage subsystem for duplication at a counterpart secondary storage subsystem, the primary subsystem including an update buffer and a data storage of multiple subparts, the method comprising the operations of:the primary subsystem receiving update requests from at least one host, each update request including update data and designation of a corresponding target primary storage subpart; and for each subpart, maintaining an update activity indicator representing update activity of that subpart; repeatedly evaluating whether update activity for any subpart has exceeded a prescribed threshold; and for each received update request, if the update activity indicator for the update request's target subpart has exceeded the threshold, selectively rejecting the update; and if the update activity indicator for the update request's designated subpart has not exceeded the threshold, storing the update data in the update buffer.