Patent ID: 6877016

Claim:
A method for developing a physically consistent snapshot at a secondary database of a primary database comprising the steps of: (a) periodically flushing buffer memories having modified data onto said primary database, and including the step of: (a1) initiating a DMUTILITY program command (QUIESCE) for managing transfer of modified data to a primary database on a primary disk (D 1 ); (b) establishing a physically consistent body of data in said primary database which is consistent with said buffered memories at a selected point in time, without denying use of said database to multiple users of read-only transactions, and including the steps of: (b1) momentarily postponing requests from user-applications (QUIESCING) until all ongoing transactions are completed after said initiation of said DMUTILITY program, and including the steps of: (b1a) flushing, at a selected point in time, of all modified buffers to said primary database (QUIESCED); (b1b) holding off all user requests momentarily until all modified data buffers, at said selected point in time, are flushed onto said primary database; (c) mirroring, at said selected point in time, all data on said primary database onto a secondary database; (d) splitting off said secondary database from said primary database to provide a snapshot-in-time, of said primary database, at the location of said secondary database.