Patent ID: 11861205
Assignee: HITACHI, LTD.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 3:
4. The distributed storage system according to claim 3, wherein
the third and fourth computers exist in a primary site,
the group storage owner volume of the third computer includes one or more primary volumes, each primary volume being a copy source in asynchronous remote copy, to which an asynchronous remote copy function is applied,
the third computer has a journal volume on the one or more primary volumes and ownership of the journal volume,
for each of the one or more primary volumes, a fifth computer exists in one of one or more secondary sites, the fifth computer having a secondary volume as a copy destination of the primary volume, the secondary volume paring with the primary volume,
the asynchronous remote copy function is a group storage function of, when data is written to a volume region in any of the primary volumes, writing a journal containing the data to the journal volume, and transferring the data in the journal written to the journal volume to a computer having a secondary volume paring with the primary volume to which the data is written,
the third computer has journal mapping data,
the journal mapping data, for each volume region in the journal volume owned by the third computer, includes domain control data indicating a volume region in a primary volume to which data contained in a journal written to the volume region is written or indicating a reflection destination region of the journal,
when the third computer verifies that the volume as the migration object from the third computer to the fourth computer is one of the primary volumes, the first fourth computer copies the domain control data on the primary volume in the journal mapping data to the fourth computer, and
the fourth computer specifies a journal and a reflection destination specified based on the copied domain control data, reads data in the journal from the physical storage region, and transfers the read data to the computer as the specified reflection destination.