DISK ARRAY DEVICE, CONTROL DEVICE AND DATA WRITE METHOD

• US 20130151771A1
• Filed: 10/12/2012
• Published: 06/13/2013
• Est. Priority Date: 12/13/2011
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: KUBOTA, Norihide, KOBAYASHI, Kenji, DAIKOKUYA, Hidejirou, IKEUCHI, Kazuhiko, TSUKAHARA, Ryota, IGASHIRA, Atsushi, WATANABE, Takeshi
• Granted Patent: US 9,128,846 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 12/0868 Data transfer between cache memory and other subsystems, e.g. storage devices or host systems
• CPC Class Codes: G06F 2211/1057 Parity-multiple bits-RAID6, i.e. RAID 6 implementations
• CPC Class Codes: G06F 2211/1059 Parity-single bit-RAID5, i.e. RAID 5 implementations
• CPC Class Codes: G06F 2212/262 configured as RAID
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A disk array device includes: a plurality of disk devices including a strip that stores divided data or a parity; a control device to divide the stripe for each of the plurality of disk devices into the divided data having a size of the strip and write the divided data; and a memory to store new data that corresponds to the divided data stored in the strip, wherein the control device detects whether or not the new data is discrete and performs a first write operation or a second write operation when the new data is discrete.

Claims

1. A disk array device comprising:

a plurality of disk devices including a strip that stores divided data or a parity;

a control device to divide the stripe for each of the plurality of disk devices into the divided data having a size of the strip and write the divided data; and

a memory to store new data that corresponds to the divided data stored in the strip,

wherein the control device detects whether or not the new data is discrete and performs a first write operation or a second write operation when the new data is discrete.

2. The disk array device according to claim 1, wherein

the first write operation includes:

issuing a read command to read, from the plurality of disk devices, a parity and data of an first strip that includes a region for writing the new data in a stripe;

reading, from the plurality of disk devices, the parity and the data of the first strip;

generating a new parity using the data of the first strip, the parity, and the new data;

generating write data by combining the new data with partial data not for updating among the data of the first strip; and

writing the write data and the new parity in the plurality of disk devices.

3. The disk array device according to claim 2, wherein:

the first write operation includes storing the parity and the data of the first strip in the memory.

4. The disk array device according to claim 1, wherein:

the first write process comprises;

issuing a read command to read, from the plurality of disk devices, data of a second strip that includes a region in which the new data in a stripe is not written;

reading, from the plurality of disk devices, the data of the second strip;

generating the new parity using the data of the second stripe and the new data;

generating the write data combining the new data with partial data not for updating among the data of the second stripe; and

writing the write data and the new parity in the plurality of disk devices.

5. The disk array device according to claim 4, wherein:

the first write operation includes recording the data in the memory.

6. The disk array device according to claim 1, wherein:

the control device selects one of the first write operation and the second write operation based on a number of disk devices to update data and the number of the plurality of disk devices.

7. The disk array device according to claim 1, wherein:

the control device selects one of the first write operation and the second write operation based on the number of strips in which the entire strip is subject to updating, the number of disk devices that update data, and the number of the plurality of disk devices.

8. A control device of a disk array device including a plurality of disk devices comprising:

performing a write operation by dividing a stripe for each of the plurality of disk devices into divided data having a size of a strip, the strip including the divided data and a parity;

determining whether or not new data corresponding to the divided data is discrete; and

performing one of a first write process and a second write process when the new data is discrete.

9. A data write method comprising:

causing a disk array device including a plurality of disk devices to perform operations of;

performing a write operation by dividing a stripe for each of the plurality of disk devices into divided data having a size of a strip, the strip including the divided data and a parity;

determining whether or not new data corresponding to the divided data is discrete; and

issuing a read command to read, from the plurality of disk devices, data of a second strip that includes a region in which the new data in a stripe is not written when the new data is discrete;

reading, from the plurality of disk devices, the data of the second strip;

generating the new parity using the data of the second stripe and the new data;

generating the write data combining the new data with partial data not for updating among the data of the second stripe; and

writing the write data and the new parity in the plurality of disk devices.