Patent ID: 7647357
Filing Date: 2010-01-12
Classification: G06F

Abstract:
1. A method of creating a consistency group, comprising: transferring segments of data identified in a first data structure, from a source of a plurality of sources to a destination of a plurality of destinations; updating, by using a computer, said first data structure to indicate a transfer of a segment of data; determining for each source at least one backlog of data segments remaining to be transferred from associated source to at least one destination; determining an estimated transfer time for each source for said first data structure as a function of the backlog associated with each source; selecting a transfer time for said first data structure as a function of said determined estimated transfer time of greatest duration; in a first mode, updating said first data structure to indicate additional segments of data to be transferred between the sources and destinations; and upon expiration of said selected transfer time, switching from said first mode to a second mode in which consistency groups are created wherein said second mode includes updating a second data structure instead of said first data structure to indicate additional segments of data to be transferred between the sources and destinations of a consistency group; upon expiration of a second time limit prior to creation of said consistency group, merging said second data structure into said first data structure and resuming said first mode, updating said first data structure instead of said second data structure to indicate additional segments of data to be transferred between sources and destinations of said consistency group; upon expiration of a selected transfer time a second time, resuming said second mode, updating said second data structure instead of said first data structure to indicate additional segments of data to be transferred between the sources and destinations of said consistency group.