International Business Machines Corporation
Intelligent space release in asynchronous mirror journal volumes

Abstract:

A method for more intelligently managing storage space in journal volumes is disclosed herein. In one embodiment, such a method includes maintaining, on a primary storage system, a change recording data structure that documents updated storage elements of a primary volume on the primary storage system. The method further determines in which extents of the primary volume the updated storage elements reside. These extents are recorded in an extent-based data structure. The method transmits the extent-based data structure from the primary storage system to a secondary storage system that is in an asynchronous mirroring relationship with the primary storage system. The extent-based data structure is then read at the secondary storage system. The method frees, from a journal volume on the secondary storage system, extents that are not recorded in the extent-based data structure. A corresponding system and computer program product are also disclosed herein.