EP0654736A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Dynamically expandable storage unit array system
Assignee: Hitachi Ltd
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Filing: 1994-11-17
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Granted: —
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Expires: 2014-11-17
Abstract
Abstract A storage unit system includes a control apparatus (1010) having a unit for reading data from a plurality of storage units (1021 to 1024) into a memory (1012) of the control apparatus prior to an increase in the number of storage units, a preparing unit for preparing parity data from the memory data read into the memory, a rearrangement unit for dispersing transfer data from a processor (1001) read into the memory and the newly prepared parity data into a plurality of storage units (1021 to 1025) after the increase to re-arrange the data, a memory unit (1035) for storing a write position during the rearrangement of data, a comparison unit for comparing an access position for an access request from the processor with the write position, and a determining unit for determining a data dispersed pattern used in a data access from the processor on the basis of a comparison result of the comparison means, whereby the storage capacity can be increased with a single storage unit, dynamically and without halting the system.
Inventors
- 👤 Kouji Arai
- 👤 Takao Satoh
- 👤 Akira Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 06:12
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/08; G06F11/10; G06F11/1076; G06F11/1096; G06F3/00; G06F3/06; G06F3/0601; G06F3/0602; G06F3/0604; G06F3/0607; G06F3/061; G06F3/0611; G06F3/0613; G06F3/0628; G06F3/0629; G06F3/0632; G06F3/0638; G06F3/064; G06F3/0655; G06F3/0658; G06F3/0668; G06F3/0671; G06F3/0683; G06F3/0689
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
282 words
An array type storage unit system comprising a plurality of storage units (1021 to 1024) and a control apparatus (1010) including means for dispersing parity data and transfer data from a processor (1001) to be stored in said plurality of storage units, means for reading necessary data from said plurality of storage units in response to a data read request from said processor to transfer the read data to said processor and means for reconstituting inaccessible data by using parity data when the data in said storage unit cannot be accessed due to a failure, wherein said control apparatus (1010) comprises: reading means (2090) for reading a predetermined number of storage data from said plurality of storage units before increase of another storage unit into a memory (1012) of said control apparatus; preparing means (2030) for preparing parity data newly from the predetermined number of storage data read in said memory of said control apparatus on the basis of a redundancy of said storage unit system; rearrangement means (2020) for dispersing the transfer data from said processor read in said memory of said control apparatus and said newly prepared parity data to be written in said plurality of storage units after the increase including a storage unit increased newly under control of said control apparatus to perform rearrangement of data; write position storing means for storing said write position on the way of said rearrangement of data; means for comparing an access position of an access request from said processor with said write position; and means (2010) for determining a data dispersed pattern used in the data access from said processor on the basis of a comparison result of said comparing means.
Claim 2
Dependent Claim
44 words
An array type storage unit system according to Claim 1, wherein said reading means of said control apparatus reads a predetermined number of storage data except parity data from said plurality of storage units before the increase into said memory of said control apparatus.
Claim 3
Dependent Claim
159 words
An array type storage unit system according to Claim 2, wherein when the number of said storage units before the increase is n (n≧1), the redundancy of parity data stored in said storage units before the increase is r (n>r≧1) and the number of said storage units after the increase is (n+k) (k≧1), said reading means of said control apparatus reads (n+k-r) data except parity data from said n storage units before the increase into said memory of said control apparatus, and said preparing means of said control apparatus prepares r parity data newly from the (n+k-r) data read in said memory of said control apparatus in accordance with the redundancy of said storage unit system, said rearrangement means of said control apparatus dispersing said (n+k-r) data read in said memory of said control apparatus and said newly prepared r parity data to be written in said (n+k) storage units after the increase to perform the rearrangement of data.
Claim 4
Dependent Claim
170 words
An array type storage unit system according to Claim 2, wherein when the number of said storage units before the increase is n (n≧1), the redundancy of parity data stored in said storage units before the increase is r (n>r≧1), the number of said storage units after the increase is (n+k) (k≧1) and the redundancy of parity data stored in said storage units after increase is (r+k), said reading means of said control apparatus reads (n-r) data except parity data from said n storage units before the increase into said memory of said control apparatus, and said preparing means of said control apparatus prepares (r+k) parity data newly from the (n-r) data read in said memory of said control apparatus in accordance with the redundancy of said storage unit system, said rearrangement means of said control apparatus writing said (n-r) data read in said memory of said control apparatus and said newly prepared (r+k) parity data into said (n+k) storage units after the increase to perform the rearrangement of data.
Claim 5
Dependent Claim
171 words
An array type storage unit system according to Claim 2, wherein when the number of said storage units before the increase is n (n≧1), the redundancy of parity data stored in said storage units before the increase is r (n>r≧1), the number of said storage units after the increase is (n+k) (k≧1) and the redundancy of parity data stored in said storage units after increase is (r+s) (0≦s≦k), said reading means of said control apparatus reads (n+k-(r+s)) data except parity data from said n storage units before the increase into said memory of said control apparatus, and said preparing means of said control apparatus prepares (r+s) parity data newly from the (n+k-(r+s)) data read in said memory of said control apparatus in accordance with the redundancy of said storage unit system, said rearrangement means of said control apparatus writing said (n+k-(r+s)) data read in said memory of said control apparatus and said newly prepared (r+s) parity data into said (n+k) storage units after the increase to perform the rearrangement of data.
Claim 6
Dependent Claim
173 words
An array type storage unit system according to Claim 1, wherein when the number of said storage units before the increase is n (n≧1), the redundancy of parity data stored in said storage units before the increase is r (n>r≧1) and the number of said storage units after the increase is (n+k) (k≧1), said reading means of said control apparatus reads (n+k) data from said n storage units before the increase into said memory of said control apparatus, and said preparing means of said control apparatus prepares r parity data newly from the (n+k-r) data except former parity data of said (n+k) data read in said memory of said control apparatus in accordance with the redundancy of said storage unit system, said rearrangement means of said control apparatus dispersing said (n+k-r) data except the former parity data of said (n+k) data read in said memory of said control apparatus and said newly prepared r parity data to be written into said (n+k) storage units after the increase to perform the rearrangement of data.
Claim 7
Dependent Claim
132 words
An array type storage unit system including a plurality of storage units (1021 to 1024) before increase, at least one storage unit (1025) after the increase and a control apparatus, wherein said control apparatus (1010) comprising: memory means (1012) for storing transfer data from a processor (1001) connected to said control apparatus; parity data preparing means (2030) for preparing parity data from said transfer data; reading means for reading said transfer data dispersed to be stored in said plurality of storage units before the increase and said parity data into said memory means; and rearrangement means (2020) for rearranging said transfer data and said parity data on the basis of previously set data rearrangement information to be stored in said storage units before the increase and said storage unit after the increase.
References Cited (Backward Citations)
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