Title:
DISK ARRAY SYSTEM
Document Type and Number:
Japanese Patent JP3234211
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To reduce an overhead when data are written in a disk array system a RAID (level 5) which distributes data and improves processing performance.
SOLUTION: In a group in which a parity is prepared, a dual area is provided. Data to be written are immediately written in the dual area when they are to be written (step 502), and writing processing to a CPU is finished at that point of time (508). Parity preparation is performed at subsequent appropriate timing (516) and written in a SCSI device (522). That is, the parity preparation is efficiently scheduled apart from data writing. Consequently, a parity preparation overhead when data are written is prevented from being seen by the CPU by writing the data to be written in the dual area and temporally processing the data writing in the SCSI device independently of parity preparation in this way when the data are written.
Inventors:
Hitoshi Tsunoda
Yoshifumi Takamoto
Yoshifumi Takamoto
Application Number:
JP2000118555A
Publication Date:
December 04, 2001
Filing Date:
May 27, 1993
Export Citation:
Assignee:
株式会社日立製作所
International Classes:
G06F12/08; G06F3/06; G06F12/10; (IPC1-7): G06F3/06; G06F12/08; G06F12/10
Domestic Patent References:
| JP1116964A | ||||
| JP63157365A | ||||
| JP594224A |
Attorney, Agent or Firm:
Katsuo Ogawa (2 outside)