EP0109309A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of operating a computer system
Assignee: Storage Technology Corp
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Filing: 1983-11-15
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Granted: —
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Expires: 2003-11-15
Abstract
Abstract When data is called from a disk memory by a host computer, the data is examined to detect embedded commands which would indicate that the data is not part of a sequential data stream. When such negative indicators are absent (NO STAGE INDICATORS OFF, 86) and provided the total amount of requested data is not large (88), one track is staged (90) into a cache memory in anticipation of a future request. If record 1 on the track was read (92) to the host, it is likely that the request is one of a sequence of requests and a flag is set (94) to indicate this. If then it is possible to de-allocate from the cache the track having the current address less two it is known that three consecutively addressed tracks have been read and an additional track is pre-staged into the cache in anticipation of continuation of the sequence.
Inventors
- 👤 P. David Dodd
- 👤 Ronald L. Blickenstaff
- 👤 Richard L. Coulson
- 👤 Robert J. Moreno
- 👤 Brian E. Trede
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 04:03
CPC Classifications
G; G06; G06F; G06F12/00; G06F12/02; G06F12/08; G06F12/0802; G06F12/0866; G06F12/0888; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1883; G06F12/0862; G06F2212/00; G06F2212/60; G06F2212/6026; G06F2212/6028; G11B2020/10916; G11B2220/00; G11B2220/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
170 words
A method of operating a computer system comprising a host computer (10) a disk memory (14), a storage director (16) which responds to commands from the host computer to supply data from the disk memory to the computer, and a high speed cache memory (22) and cache manager (24) arranged to stage selected portions of data from the disk memory into the cache memory in anticipation of its requirement, characterised in that series of commands from the host computer (10) are examined to determine whether any one data request is likely to be one of a series of such requests, staging a first amount of data not called for by the host computer from the disk memory (14) to the cache memory (22) in response to each data request, regardless of the outcome of the determination, and staging a second, additional amount of data from the disk memory to the cache memory if the determination indicates that the request appears likely to be one of a series of such requests.
Claim 2
Independent Claim
170 words
A method of operating a computer system comprising a host computer (10) a disk memory (14), a storage director (16) which responds to commands from the host computer to supply data from the disk memory to the computer, and a high speed cache memory (22) and cache manager (24) arranged to stage selected portions of data from the disk memory into the cache memory in anticipation of its requirement, characterised in that series of commands from the host computer (10) are examined to determine whether any one data request is likely to be one of a series of such requests, staging a first amount of data not called for by the host computer from the disk memory (14) to the cache memory (22) in response to each data request, regardless of the outcome of the determination, and staging a second, additional amount of data from the disk memory to the cache memory if the determination indicates that the request appears likely to be one of a series of such requests.
Claim 3
Dependent Claim
33 words
2- A method according to claim 1, characterised in that the first amount of data is at most one disk track and the second amount of data is at least one disk track.
Claim 4
Independent Claim
157 words
A method for control of a cache memory subsystem adapted to be connected to a host computer, said subsystem comprising solid-state cache storage means and cache manager means, said cache manager being adapted to examine signals passed between a host computer and a storage director, and to output cache control signals to control the flow of data from magnetic data storage means through said director into said cache storage means and from said cache storage means through said director to said host, said cache manager examining control signals output by said host during the satisfaction of a host read request and determining from said signals, after satisfaction of said request, whether or not said request is likely to be one of a sequence of such requests, and if so, for controlling flow of additional data not called for by said host into said cache storage means, in anticipation of requests for such additional data by said host.
Claim 5
Independent Claim
157 words
A method for control of a cache memory subsystem adapted to be connected to a host computer, said subsystem comprising solid-state cache storage means and cache manager means, said cache manager being adapted to examine signals passed between a host computer and a storage director, and to output cache control signals to control the flow of data from magnetic data storage means through said director into said cache storage means and from said cache storage means through said director to said host, said cache manager examining control signals output by said host during the satisfaction of a host read request and determining from said signals, after satisfaction of said request, whether or not said request is likely to be one of a sequence of such requests, and if so, for controlling flow of additional data not called for by said host into said cache storage means, in anticipation of requests for such additional data by said host.
References Cited (Backward Citations)
No citation records indexed.
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