EP0889410A2
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EP
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Method and apparatus for high availability and caching data storage devices
Assignee: Sun Microsystems Inc
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Filing: 1998-06-25
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Granted: —
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Expires: 2018-06-25
Abstract
Abstract A method and apparatus for high availability and caching data storage devices. According to a preferred embodiment of the invention, there is provided an apparatus. The apparatus comprises a primary controller, a secondary controller having the same address as that of the primary controller, a switching circuit coupled to the primary and secondary controllers, and a control circuit coupled to the switching circuit. According to this preferred embodiment of the invention, in a normal operation, the control circuit sets the switching circuit so that the primary controller receives and responds to input data supplied from a host, and the secondary controller receives the input data. In a fail-over operation in which the primary controller fails, the control circuit sets the switching circuit so that the primary controller is disabled, and the secondary controller receives and responds to the input data supplied from the host. The fail-over is transparent to the host. The apparatus may further comprise a data storage device coupled to both the primary and secondary controllers. An alternative preferred embodiment of the invention is also provided.
Inventors
- 👤 Fay Chong
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 18:50
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/16; G06F11/20; G06F11/2053; G06F11/2089; G06F11/2092; G06F11/2097
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
126 words
An apparatus, responsive to a host, for high availability and caching data
storage devices, comprising: a primary controller; a secondary controller having the same address as that of the primary
controller; a switching circuit coupled to the primary and secondary controllers; and a control circuit coupled to the switching circuit; wherein in a normal operation, the control circuit sets the switching circuit so
that the primary controller receives and responds to input data supplied from the
host and the secondary controller receives the input data; and wherein in a fail-over operation in which the primary controller fails, the control
circuit sets the switching circuit so that the primary controller is disabled and the
secondary controller receives and responds to the input data supplied from the host.
Claim 2
Dependent Claim
46 words
The apparatus of claim 1, wherein the switching circuit includes first and second multiplexers coupled to
the primary and secondary controllers, respectively; wherein the control circuit switches the first and second multiplexers to control
the primary and secondary controllers, respectively, in the normal and fail-over
operations.
Claim 3
Dependent Claim
21 words
The apparatus of claim 2, wherein the primary controller includes a first
cache and the secondary controller includes a second cache.
Claim 4
Dependent Claim
19 words
The apparatus of claim 2, further comprising a data storage device coupled
to both the primary and secondary controllers.
Claim 5
Independent Claim
136 words
A method for providing high availability and caching for data storage
devices, comprising the steps of: (a) providing a primary controller; (b) providing a secondary controller having the same address as that of the
primary controller; (c) coupling a switching circuit to the primary and secondary controllers; (d) coupling a control circuit to the switching circuit; (e) controlling, in a normal operation, the control circuit to set the switching
circuit so that the primary controller receives and responds to input data supplied
from a host and the secondary controller receives the input data; and (f) controlling, in a fail-over operation in which the primary controller fails, the
control circuit to set the switching circuit so that the primary controller is disabled and
the secondary controller receives and responds to the input data supplied from the
host.
Claim 6
Dependent Claim
52 words
The method of claim 5, wherein the switching circuit includes first and second multiplexers coupled to
the primary and secondary controllers, respectively; wherein each of steps (e) and (f) comprises the step of controlling the control
circuit to switch the first and second multiplexers to control the primary and
secondary controllers, respectively.
Claim 7
Dependent Claim
21 words
The method of claim 6, wherein the primary controller includes a first cache
and the secondary controller includes a second cache.
Claim 8
Dependent Claim
22 words
The method of claim 6, further comprising the step of coupling a data
storage device to both the primary and secondary controllers.
Claim 9
Independent Claim
260 words
An apparatus, responsive to first and second hosts, for high availability and
caching for data storage devices, comprising: a first controller including a first primary controller and a second secondary
controller; a second controller including a second primary controller and a first
secondary controller, wherein the first secondary controller is a backup of the first
primary controller and the second secondary controller is a backup of the second
primary controller; a switching circuit set coupled to the first and second controllers; and a control circuit coupled to the switching circuit set; wherein in a normal operation, the control circuit sets the switching circuit set
so that the first primary controller receives and responds to input data supplied from
the first host and the first secondary controller receives the input data from the first
host, and the second primary controller receives and responds to input data supplied
from the second host and the second secondary controller receives the input data
from the second host; and wherein in a fail-over operation in which one of the first and second
controllers fails and becomes a failing controller and the other of the first and second
controllers becomes a surviving controller, the control circuit sets the switching
circuit set so that the primary controller in the failing controller is disabled and the
secondary controller in the surviving controller receives and responds to the input
data directed to the primary controller in the failing controller, and the primary
controller in the surviving controller receives and responds to the input data directed
to the surviving controller.
Claim 10
Dependent Claim
49 words
The apparatus of claim 9, wherein the switching circuit set includes: a first switching circuit coupled to the first primary controller and the
secondary controller in the first controller; and a second switching circuit coupled to the second primary controller and the
first secondary controller in the second controller.
Claim 11
Dependent Claim
81 words
The apparatus of claim 10, wherein the first switching circuit comprises first and second multiplexers, and
the second switching circuit comprises third and fourth multiplexers; wherein the control circuit includes first and second control circuits; wherein the first control circuit switches the first and second multiplexers to
control the first primary controller and the first secondary controller, respectively, and
the second control circuit switches the third and fourth multiplexers to control the
second primary controller and the second secondary controller, respectively.
Claim 12
Dependent Claim
43 words
The apparatus of claim 11, wherein the first controller includes a first cache coupled to the first primary
controller and the second secondary controller; wherein the second controller includes a second cache coupled to the second
primary controller and the first secondary controller.
Claim 13
Dependent Claim
21 words
The apparatus of claim 11, further comprising first and second data
storage devices each coupled to both first and second controllers.
Claim 14
Dependent Claim
13 words
The apparatus of claim 9, wherein the circuitry is a fiber channel circuitry.
References Cited (Backward Citations)
No citation records indexed.
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