External storage system
First Claim
1. An external storage system comprising:
- a storage unit for storing data to be transferred to and from an upper level system;
a plurality of storage controllers provided between said storage unit and said upper level system for controlling data transfer between said upper level system and said storage unit; and
a management memory accessible by the plurality of storage controllers for storing management information of the plurality of storage controllers,wherein a first storage controller for receiving an input-output request from said upper level system stores said input-output request in said management memory as load distribution information, anda second storage controller refers to said load distribution information and processes said input/output request received by said first storage controller.
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Accused Products
Abstract
An external storage system has a storage unit for storing data and a plurality of storage controllers for controlling data transfer between an upper level system and the storage unit. Each storage controller has a data buffer for temporarily storing data and a controller for controlling the operation of the storage controller. The external storage system has a management memory for storing management information of the plurality of storage controllers each of which accesses this memory to monitor the operation states of other storage controllers. The external storage system has a first storage controller for processing an input-output request from the upper level system and a second storage controller for standing by for backup for a failed storage controller. In accordance with load distribution information stored in the management memory, the process to be executed by the first storage controller is partially executed by the second storage controller to improve the performance of the whole external storage system.
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Citations
20 Claims
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1. An external storage system comprising:
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a storage unit for storing data to be transferred to and from an upper level system; a plurality of storage controllers provided between said storage unit and said upper level system for controlling data transfer between said upper level system and said storage unit; and a management memory accessible by the plurality of storage controllers for storing management information of the plurality of storage controllers, wherein a first storage controller for receiving an input-output request from said upper level system stores said input-output request in said management memory as load distribution information, and a second storage controller refers to said load distribution information and processes said input/output request received by said first storage controller. - View Dependent Claims (2, 3, 4, 5)
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6. An external storage system comprising:
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a storage unit for storing data to be transferred to and from an upper level system; a plurality of storage controllers provided between said storage unit and said upper level system for controlling data transfer between said upper level system and said storage unit, the plurality of storage controllers each having switching means for switching to one of the storage controllers which controls the data transfer to and from said upper level system; and a management memory accessible by the plurality of storage controllers for storing information on the states of the plurality of storage controllers, wherein a first storage controller monitors a presence/absence of a failure of a second storage controller by referring to said management memory, and the second storage controller with a failure is disconnected. - View Dependent Claims (7, 8, 9, 10, 11)
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12. An external storage system comprising:
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a storage unit for storing data to be transferred to and from an upper level system; a plurality of storage controllers provided between said storage unit and said upper level system for controlling data transfer between said upper level system and said storage unit, the plurality of storage controllers each including switching means for switching to one of the storage controllers which controls the data transfer to and from said upper level system; communication means for communicating with the plurality of storage controllers; and a management memory accessible by the plurality of storage controllers for storing information on the states of the plurality of storage controllers, wherein when a maintenance request is issued to the plurality of storage controllers; a first storage controller controls the data transfer between the upper level system and the storage unit, and maintenance is performed by disconnecting a second storage controller; when said second storage controller is recovered to a normal state, a notice of recover is sent to said first storage controller by using said communication means, and said first storage controller is changed to said second storage controller by said switching means as the storage controller for the data transfer to and from said upper level system; said second storage controller controls the data transfer between said upper level system and said storage unit and said first storage controller recognized the notice is disconnected for maintenance; and when said first storage controller is recovered to a normal state, a notice of recover is sent to said second storage controller by using said communication means, and said second storage controller recognizes the notice. - View Dependent Claims (13)
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14. An external storage system comprising:
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a storage unit for storing data to be transferred to and from an upper level system; a plurality of storage controllers provided between said storage unit and said upper level system for controlling data transfer between said upper level system and said storage unit, the plurality of storage controllers each including;
a data buffer for temporarily storing the data;
a data transfer controller for controlling data transfer between said upper level system and said data buffer and for transferring said data between said data buffers of said plurality of storage controllers including said data buffer of its own storage controllers; and
a DRV transfer controller for controlling data transfer between said data buffer and said storage unit;a common management memory accessible by the plurality of storage controllers for storing management information of the plurality of storage controllers; and communication means for communicating with the plurality of storage controllers. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification