Nelson and Nelson
Space reclamation in asynchronously mirrored space-efficient secondary volumes
A method for releasing storage space in asynchronously mirrored space-efficient secondary volumes is disclosed. In one embodiment, such a method includes reading a first copy of a free-space data structure stored on a space-efficient secondary volume. The free-space data structure tracks the usage status of storage elements in the space-efficient secondary volume. The method analyzes the first copy to determine which storage elements in the space-efficient secondary volume are not being used. Upon completion of a consistency group on the space-efficient secondary volume, the method reads a second copy of the free-space data structure and compares the first copy to the second copy to determine which storage elements had their usage status change during analysis of the first copy. The method releases storage elements in the space-efficient secondary volume that are not being used. A corresponding system and computer program product are also disclosed.
International Business Machines Corporation
G G G G
G06F G06F G06F G06F
inventional inventional inventional inventional
Gregory E. Carol S. David C. Theresa M.
McBride Mellgren Reed Brown