External storage and data recovery method for external storage as well as program
First Claim
1. An external storage to be connected to a host computer, comprising:
- storing means which stores data to be used by the host computer; and
control means which controls the storing means, wherein the control means comprises;
registering means which registers a recoverable point to be set by the host computer concerning data stored in the storing means, said recoverable point corresponding to journal data which includes journal control information having information necessary for recovering data on the storing means to the recoverable point and a recovery flag which is settable by the host computer to indicate that the journal data is a recoverable point;
information for selection sending means which sends information for selection related to the journal data at the registered recoverable point to the host computer in response to a request from the host computer; and
recovering means which recovers data designated by the host computer to a designated recoverable point based on the information for selection related to the journal data at the recoverable point.
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Accused Products
Abstract
The data is automatically recovered to a desired arbitrary point in an external storage without imposing a burden on the host computer. An application on a host computer instructs data recovery control processing of a disk control apparatus to set a recovery opportunity. It is possible to register arbitrary plural points as a recoverable point by setting a recovery flag included in journal data. In the case in which data is recovered due to occurrence of a failure or the like, the application requests a list showing recovery opportunities which have already been set. The application designates a point to which data is recovered on the basis of the recovery opportunity list. The disk control apparatus recovers the data to the designated point on the basis of a backup disk and a journal disk.
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Citations
1 Claim
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1. An external storage to be connected to a host computer, comprising:
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storing means which stores data to be used by the host computer; and
control means which controls the storing means, wherein the control means comprises;
registering means which registers a recoverable point to be set by the host computer concerning data stored in the storing means, said recoverable point corresponding to journal data which includes journal control information having information necessary for recovering data on the storing means to the recoverable point and a recovery flag which is settable by the host computer to indicate that the journal data is a recoverable point;
information for selection sending means which sends information for selection related to the journal data at the registered recoverable point to the host computer in response to a request from the host computer; and
recovering means which recovers data designated by the host computer to a designated recoverable point based on the information for selection related to the journal data at the recoverable point.
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Specification