Patent ID: 7017003
Filing Date: 2006-03-21
Classification: G06F

Abstract:
1. A disk control apparatus connected to an information processing apparatus so as to be able to communicate with the information processing apparatus, the disk control apparatus writing/reading data into/from a first storage device having one or more logical volumes formed thereon, a second storage device having one or more logical volumes formed thereon, and a third storage device, the disk control apparatus comprising: a memory, association of identifiers of the logical volumes in said first storage device serving as identifiers of primary logical volumes with identifiers of the logical volumes in said second storage device serving as identifiers of secondary logical volumes being stored in said memory as a pair management table; a timing mechanism; a write request reception unit for receiving a write request of update data for a logical volume in said first storage device and the update data to be written, from the information processing apparatus; a first write unit responsive to reception of the write request, for writing the update data into the logical volume in said first storage device; a journal write unit for writing journal data into said third storage device, each of the journal data comprising an identifier of a respective logical volume in said first storage device into which the journal data has been written, information of a location in which the journal data is stored in the respective logical volume, update time which is a current time acquired from said timing mechanism, and update data; and a second write unit for referring to the update time of the journal data stored in said third storage device, selecting at least one of the journal data for which a difference between a respective current time acquired from said timing mechanism and the update time is longer than a predetermined time, referring to an identifier of the logical volume in the selected journal data, the location information and the update data therein in an updating time order, acquiring an identifier of a secondary logical volume corresponding to the identifier of the logical volume in the selected journal data in the pair management table, and writing the update data in the selected journal data into a place indicated by the location information in the selected journal data, which is a logical volume indicated by the identifier of the secondary logical volume, in said second storage device.