US 12,073,089 B2
Storage device and data recovery method by storage device
Kenichi Betsuno, Tokyo (JP); Akira Yamamoto, Tokyo (JP); Takashi Nagao, Tokyo (JP); and Kazuki Matsugami, Tokyo (JP)
Assigned to Hitachi, Ltd., Tokyo (JP)
Filed by Hitachi, Ltd., Tokyo (JP)
Filed on Sep. 19, 2022, as Appl. No. 17/947,905.
Claims priority of application No. 2022-042708 (JP), filed on Mar. 17, 2022.
Prior Publication US 2023/0297242 A1, Sep. 21, 2023
Int. Cl. G06F 3/06 (2006.01); G06F 11/10 (2006.01); G06F 12/02 (2006.01)
CPC G06F 3/0616 (2013.01) [G06F 3/0631 (2013.01); G06F 11/10 (2013.01); G06F 3/0683 (2013.01); G06F 12/0253 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A storage device that manages data stored in a storage drive in a plurality of logical hierarchies, the storage device comprising:
a host interface that communicates with a host; and
a processor; wherein
the plurality of logical hierarchies include a writing hierarchy above a hierarchy of a parity group including a plurality of storage drives; and
the processor
writes host data received via the host interface to a free area in the writing hierarchy, and
executes, in a data recovery process for replacing a failure storage drive with a new storage drive, a garbage collection process on a first logical area in the writing hierarchy associated with a first parity group including the failure storage drive, and
in the garbage collection process, valid data is selected from the first logical area and copied to a second logical area associated with a second parity group different from the first parity group,
wherein the processor determines to execute the garbage collection process on a logical area in the writing hierarchy associated with the first parity group in which a garbage amount is greater than or equal to a first threshold value,
wherein the processor executes the garbage collection process on a logical area where a garbage amount is greater than or equal to a second threshold value among logical areas in the writing hierarchy allocated to a parity group including a normal storage drive outside the data recovery process, and
the first threshold value is less than or equal to the second threshold value.