Patent ID: 6081875
Filing Date: 2000-06-27
Classification: G06F

Abstract:
In a data processing system having a host computer connected to a disk peripheral, a backup computer connected to a host computer and the disk peripheral, and a tape peripheral connected to the backup computer, a method for creating a snapshot image of a desired portion of the data residing on the disk peripheral comprising the steps of:(a) reading a block of the desired portion of the data from the disk peripheral(b) determining if a block previously read from the same disk peripheral address as the block read in step (a) is available in an original data cache;(c) if step (b) is affirmative, transferring the previously read block of data to the tape peripheral;(d) if step (b) is not affirmative, transferring the block of data read in step (a) to the tape peripheral; and(e) repeating steps (a)-(d) until the entire desired portion has been transferred to the tape peripheral.