US 11,836,110 B2
Storage system, computer system, and control method
Takaki Matsushita, Tokyo (JP); and Akira Deguchi, Tokyo (JP)
Assigned to HITACHI, LTD., Tokyo (JP)
Filed by Hitachi, Ltd., Tokyo (JP)
Filed on Mar. 11, 2022, as Appl. No. 17/692,964.
Claims priority of application No. 2021-102223 (JP), filed on Jun. 21, 2021.
Prior Publication US 2022/0405237 A1, Dec. 22, 2022
Int. Cl. G06F 16/10 (2019.01); G06F 16/11 (2019.01); G06F 16/188 (2019.01); G06F 11/14 (2006.01); G06F 16/178 (2019.01)
CPC G06F 16/128 (2019.01) [G06F 11/1451 (2013.01); G06F 11/1458 (2013.01); G06F 16/178 (2019.01); G06F 16/188 (2019.01)] 12 Claims
OG exemplary drawing
 
1. A storage system connected to an other storage system via a network, the storage system comprising:
a memory;
a processor configured to execute a program stored in the memory; and
a storage device, wherein
by executing the program, the processor
provides a virtual volume,
generates a plurality of snapshots at different timings for the virtual volume, wherein each of the plurality of snapshots includes at least a first data and a second data,
holds a base snapshot, which is a reference snapshot among the plurality of snapshots, in the storage device, and includes first data and second data,
a first snapshot, generated at a timing after the base snapshot, updates the first data to first data one,
a second snapshot, generated at a timing after the first snapshot, updates the first data one to first data two,
a third snapshot, generated at a timing after the second snapshot, maintains the first data two and updates the second data to second data one,
determines a first difference data between the base snapshot and the first snapshot and transmits the first difference data to a volume in the other storage system,
determines a second difference data between the first snapshot and the second snapshot and transmits the second difference data to a different volume in the other storage system, and
deletes the first snapshot from the storage system and holds the first difference data and the second difference data in the other storage system.