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US 6,557,140 B2Granted
Disk array system and its control method
AssigneeHitachi, Ltd.
InventorsHitoshi Kakuta, Yoshifumi Takamoto
Life of this patent
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Abstract
In a disk array system of RAID (level 5) improving the system performance by distributing data, duplicated fields are allocated in a parity group in order to reduce an overhead of data write. In the data write process, write data is tentatively and duplicately written in the duplicate fields. At this time, a write completion is reported to CPU. The parity is generated later at a proper timing and written in a SCSI drive. Generating a parity and writing data can be efficiently scheduled.
Claims4
A disk array system connected to a CPU, comprising:
- a controller with a first memory, and
- a plurality of disk drives connected to said controller,
- wherein a non-volatile memory stores an address table that is used for converting a logical address that the CPU designates into a physical address of said disk drives, and
- wherein said controller reads the address table from said non-volatile memory into said first memory when the disk array system power is turned on, and stores the address table from the first memory into said non-volatile memory when the disk array system power is turned off, said address table being updated upon occurrence of a failure in any of said plurality of disk drives.
1 more element
Dependencies are inferred from the claim text.