Patent ID: 6754682
Filing Date: 2004-06-22
Classification: G06F,Y10S

Abstract:
In a data processing system including a host and at least one disk array storage device including a plurality of first logical devices for interacting with a first application and including a second logical device corresponding to each first logical device that can interact in a first mode as a mirror for a corresponding first logical device and that can interact in a second mode with a second application with read and write capabilities, a method comprising:A) issuing a command to shift a group of a plurality of identified second logical devices from the first mode to the second mode in a consistent fashion, B) generating a request data structure for each of the group of second logical devices identified in the command, C) disabling all interactions between the first application and all the first logical devices corresponding to the second logical devices in the group, D) initiating a shift all of the identified second logical devices in the group to the second mode after said disablement, E) enabling, upon completion of said shifting, the resumption of interactions between the first application and all the first logical devices corresponding to the identified second logical devices in the group, and F) generating a return to the host indicating that the shift to the second mode has been completed whereupon the data in each of the identified second logical devices in the group is consistent whereby the second application can interact with the data in the identified second logical devices concurrently with interaction of the first application with data in the first logical devices.