Patent ID: 7228396

Claim:
A method of transitioning from a first data transfer mode to a second data transfer mode that is different from the first data transfer mode, the method comprising: a primary storage device receiving a plurality of data writes while being in the first data transfer mode; the primary storage device associating data writes begun after a first time and before a second time with a first chunk of data; the primary storage device associating data writes begun after the second time with a second chunk of data different from the first chunk of data; and the primary storage device transitioning to the second data transfer mode after the second time by first transferring writes associated with the first chunk of data to a secondary storage device after completion of all writes to the primary storage device associated with the first chunk of data and then, after all writes associated with the first chunk of data have been transferred to the secondary storage device, transferring at least a portion of writes associated with the second chunk of data to the secondary storage device using the first data transfer mode, wherein writes begun after initiating transitioning are merged with any corresponding data written using the first data transfer mode prior to being provided to the secondary storage device using the second data transfer mode.