Patent ID: 8458425
Filing Date: 2013-06-04
Classification: G06F

Abstract:
1. A computer-readable, non-transitory medium storing a data management program for use in a multi-node storage system formed from a plurality of disk nodes each managing a storage device to store data in a distributed manner, the data management program, when executed by a computer serving as one of the disk nodes, causing the computer to perform a procedure comprising: allocating one of constituent storage spaces in a storage device coupled to the computer, to one of data units constituting a logical volume that provides a virtual storage space, in response to a write request specifying the one of data units as a destination of write data, and writing the write data to the allocated constituent storage space; recording, upon the writing of the write data, a current time in a data unit record memory as a record of last write time of the data unit to which the write data has been written; detecting, by consulting the data unit information memory, a data unit whose deduplication grace period after the last write time has expired; obtaining, from an index server, one of deduplication addresses that is associated with a first unique value obtained by applying a predetermined computation to data stored in the constituent storage space allocated to the detected data unit, wherein the index server manages the deduplication addresses each including an identifier of a disk node managing a deduplicate unit and a second unique value obtained by applying the predetermined computation to deduplication target data stored in the deduplicate unit, and wherein the deduplicate unit is provided in a plurality to constitute a deduplicate volume that provides another virtual storage space; and storing the obtained deduplication address in the data unit record memory, together with the detected data unit, and canceling the allocation of the constituent storage spaces to the detected data unit.