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

Claim 0:
1. A volume migration method for migrating a volume between computers among a plurality of computers configuring a distributed storage system,
the respective plurality of computers being accessibly connected via a communication network to one or more physical storage devices in a storage unit,
for each of the plurality of computers,
the computer performing input/output (I/O) of data to/from an owner volume of which the ownership is owned by the computer,
the computer writing data, the data being written into a volume region as a write destination of the owner volume of the computer, into a storage region allocated to the volume region as the write destination in a physical storage region provided by the one or more physical storage devices,
the computer having domain mapping data indicating a relationship between a volume region in the owner volume of the computer and a storage region in the physical storage region and being metadata for the owner volume,
wherein in the volume migration method,
the third computer identifies that a volume as a migration object from a third computer to a fourth computer is a storage owner volume,
the storage owner volume is an owner volume to which a storage function is applied, the storage function requiring control data for I/O of data, the control data being metadata other than the domain mapping data, in place of or in addition to the domain mapping data,
the third computer migrates ownership of the storage owner volume to the fourth computer, and copies the control data of the storage owner volume to the fourth computer, wherein
the physical storage devices have different I/O performances,
the storage owner volume of the third computer is an auto tiering owner volume being an owner volume to which an auto tiering function is applied,
the auto tiering function is a storage function performing auto tiering of changing a physical storage device as a location destination of data written into a volume region in the storage owner volume according to I/O frequency of the volume region at regular intervals or every time a predetermined event occurs,
the third computer has I/O statistical data as control data indicating a correspondence relationship between the volume region and the I/O frequency for the auto tiering owner volume,
when the third computer identifies that the volume as the migration object from the third computer to the fourth computer is the auto tiering owner volume,
copying by the third computer, to the fourth computer, a domain mapping data of the auto tiering owner volume and the I/O statistical data for the auto tiering owner volume, and
after the auto tiering owner volume is migrated to the fourth computer,
updating by the fourth computer the copied I/O statistical data according to I/O to/from the auto tiering owner volume, and performing auto tiering for the auto tiering owner volume based on the I/O statistical data.