EP0632379A2
Expired / Lapsed
EP
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Fault tolerant storage controller utilizing tightly coupled dual controller modules
Assignee: Hewlett Packard Development Co LP
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Filing: 1994-06-06
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Granted: —
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Expires: 2014-06-06
Abstract
Abstract A fault tolerant storage controller utilizing tightly coupled dual controller modules. The controller modules each check to see if another controller module or cache module is present and, if so, then all configuration information with respect to the controller modules and attached devices are shared between them. Configuration information may be entered into either or both of the controller modules and the information is shared dynamically. Each cache module may be "locked" by an individual controller module to prevent the other controller module from inadvertently disturbing the contents of the other controller module's cache. During initialization, each controller module checks for the existence of an associated cache module and, if present, it is immediately "locked" by the controller module. Should a controller module fail or give an indication of a malfunction, the other controller module will disable or "kill" the malfunctioning controller module thereby resetting it and releasing any lock it may have had on its cache module. In those instances where the cache module is a write cache, the surviving controller module can resume operations where the malfunctioning controller module left off and complete any remaining writes to the disabled controller module's storage devices preventing the loss of any host computer data. The controller modules are tolerant of the other controller module failing and then rebooting and the sequence of events is detected and recognized by the surviving controller module such that it does not disable the one that failed. The dual controller modules communicate asynchronously to verify that they are each operational and to exchange and verify configuration information and to provide operational status dynamically.
Inventors
- 👤 Stephen J. Sicola
- 👤 James P. Jackson
- 👤 Roger L. Oakey
- 👤 Richard G. Brame
- 👤 Ronald H. Mclean
- 👤 Michael D. Walker
- 👤 Thomas F. Fava
- 👤 Thomas Gene Adams
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 03:41
CPC Classifications
G; G06; G06F; G06F15/00; G06F15/16; G06F11/00; G06F11/07; G06F11/16; G06F11/20; G06F11/2053; G06F11/2089; G06F11/08; G06F11/10; G06F11/1008; G06F11/1658; G06F11/1662; G06F11/2002; G06F11/2007; G06F11/201; G06F11/2097
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
229 words
A computer mass storage device controller system comprising: first and second controller modules operatively coupled to a plurality of computer mass storage devices, said first controller module controlling a first subset of said plurality of computer mass storage devices and said second controller module controlling a second subset of said plurality of computer mass storage devices; a first signal line communicating between said first and second controller modules to indicate the presence of said first controller module to said second controller module and said second controller module to said first controller module; a communications channel interconnecting said first and second controller modules, said first and second controller modules being responsive to a controller present signal on said first signal line to enable communications between said first and second controller modules over said communications channel; and a second signal line coupling said first and second controller modules, means enabling said first controller module to functionally disable said second controller module in response to an indication on said communications channel that said second controller module may have malfunctioned, including means for said first controller to unlock and assume control of said second subset of said plurality of computer mass storage devices, said controller system further comprising means to prevent each controller module when properly functioning from disturbing contents of mass storage devices corresponding to the other controller module when properly functioning.
Claim 2
Dependent Claim
98 words
The computer mass storage device controller system of claim 1 further comprising: first and second data cache modules operatively coupled to said first and second controller modules by respective first data paths, said first and second data cache modules further having alternative second data paths for operatively coupling said first and second controller modules to said second and first data cache modules respectively, wherein said first controller module is further operatively coupled to said second data cache module by said second data path upon assuming control of said second subset of said plurality of computer mass storage devices.
Claim 3
Dependent Claim
71 words
The computer mass storage device controller system of claim 1 wherein said first and second signal lines and said communications channel comprise a backplane into which said first and second controller modules are electrically coupled, wherein said communications channel, comprises an asynchronous communications channel, wherein said asynchronous communications channel comprises first and second unidirectional communications lines, said computer mass storage device controller system further comprising first and second clear-to-send signal lines.
Claim 4
Dependent Claim
176 words
A fault tolerant computer mass storage device controller comprising: first and second controller modules for operative coupling to a plurality of computer mass storage devices, said first controller module for controlling a first subset of said plurality of computer mass storage devices and said second controller module for controlling a second subset of said plurality of computer mass storage devices; and a plurality of communications lines interconnecting said first and second controller modules; said communications lines for providing configuration and operational information between said first and second controller modules, said communications lines further including a controller module disable line for assertion by either of said controller modules to operatively disable an other of said controller modules in response to a malfunction indication from said other of said controller modules; means for enabling said first controller module operatively to disable a malfunctioning second controller module by asserting said controller module disable line, and means for said first controller module additionally assuming access to and control of said second subset of said plurality of computer mass storage devices.
Claim 5
Dependent Claim
99 words
The fault tolerant computer mass storage device controller of claim 4 further comprising: first and second data cache modules operatively coupled to said first and second controller modules by respective first data paths, said first and second data cache modules further having alternative second data paths for operatively coupling said first and second controller modules to said second and first data cache modules respectively, wherein said first controller module is further operatively coupled to said second data cache module by said second data path upon assuming control of said second subset of said plurality of computer mass storage devices.
Claim 6
Dependent Claim
192 words
A computer mass storage device controller system comprising: first and second controller modules for operative coupling to a plurality of computer mass storage devices, said first controller module for controlling a first subset of said plurality of computer mass storage devices and said second controller module for controlling a second subset of said plurality of computer mass storage devices; and a communications medium interconnecting said first and second controller modules, said communications medium for conveying an indication signal showing a controller presence, from one of said controller modules to the other of said controller modules when said one of said controller modules is included in said system, said communications medium including a plurality of controller module communications lines for communications between said first and second controller modules when said controller present indication is detected by both said first and second controller modules, said controller system including means to send a message to said second controller that said first controller is booting and means to disable a second malfunctioning controller as well as means to unlock and gain access to and unlock said second subset of said plurality of computer mass storage devices.
Claim 7
Dependent Claim
98 words
The computer mass storage device controller system of claim 6 further comprising: first and second data cache modules operatively coupled to said first and second controller modules by respective first data paths, said first and second data cache modules further having alternative second data paths for operatively coupling said first and second controller modules to said second and first data cache modules respectively, wherein said first controller module is further operatively coupled to said second data cache module by said second data path upon assuming control of said second subset of said plurality of computer mass storage devices.
Claim 8
Dependent Claim
46 words
The computer mass storage device controller system of claim 6 wherein said plurality of communications medium comprises a backplane into which said first and second controller modules are electrically coupled, wherein communications between said first and second controller modules on said communications medium are conducted asynchronously.
Claim 9
Dependent Claim
22 words
The computer mass storage device controller system of claim 8 wherein said communications medium further comprises first and second clear-to-send signal lines.
Claim 10
Dependent Claim
43 words
The computer mass storage device controller system of claim 6 wherein said other of said controller modules is precluded from functionally disabling said one of said controller modules once said one of said controller modules has disabled said other of said controller modules.
References Cited (Backward Citations)
No citation records indexed.
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