Restore method for backup
First Claim
1. An image restore method executed in a storage system comprising:
- a disk array storage system comprising a disk drive in which a primary volume used by a server for some purpose is set from/to which data is read and written, a block device interface that sends and receives data and control signals to/from a computer, a disk interface that sends and receives data and control signals to/from with the disk drive, a memory that stores a control program, and a CPU that executes the control program to control input and output of the data to/from the disk drive; and
a backup management device that manages backup and restore of the data stored in the disk array storage system using a full backup image obtained by copying a whole of the data stored in the primary volume at a predetermined timing and each delta image obtained by copying a data changed after one of the full backup and delta backup, the image restore method comprising;
creating a temporary restored image by applying each required delta image to the full backup image and storing the temporary restored image in a restore destination volume;
judging whether the reverse delta image and a cost table of applying delta relating to each applied the delta image have been created, with each reverse delta image recording the reverse delta image before the application of the applied delta image and the cost table of applying delta recording a number of blocks of the applied delta image;
creating, if the reverse delta image and the cost table of applying delta relating to the applied delta image are not yet created, the reverse delta image related to the applied delta image and recording a number of delta application blocks relating to the applied delta image in the cost table of applying delta;
judging whether an intended restore target has been restored with reference to a backup creation date and time recorded in a delta backup management table;
recording, if it is judged that the intended restore target has been restored, a backup date and time of the restore target; and
creating, if it is not judged that the intended restore target has been restored, a new temporary restored image, calculating a sum of a number of blocks of each reverse delta image that should be applied to the temporary restored image in order to reach the intended restore target with reference to the cost table of applying delta, and obtaining a number of blocks that is changed when restore is performed by applying the reverse delta image;
calculating a sum of a number of blocks of the full backup image and a total number of blocks of each delta image that should be applied to the full backup image in order to reach the intended restore target with reference to the cost table of applying delta, and obtaining a number of blocks that is changed when the restore is performed by applying the delta image;
comparing the number of blocks that is changed when the restore is performed by applying the reverse delta image with the number of blocks that is changed when the restore is performed by applying the delta image;
performing the restore by applying the reverse delta image that is necessary in order to reach an intended restore target, to the temporary restored image if the restore through the application of the reverse delta image results in a fewer number of blocks to be changed; and
performing the restore by sequentially applying the delta image that is necessary in order to reach an intended restore target, to the full backup image if the restore through the application of the delta image results in a fewer number of blocks to be changed.
1 Assignment
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Accused Products
Abstract
To provide a storage management device capable of performing restore at a high speed. In the storage management device that manages backup and restore of data stored in a storage device, a temporary restored image is created by applying each required delta image to the full backup image, a reverse delta image before the application of the applied delta image is created, and a number of delta application blocks concerning the applied delta image is recorded as cost information of applying delta. The delta backup restore unit determines a restore method by comparing a number of blocks, which is changed when restore is performed by applying each piece of the reverse delta image, with a number of blocks, which is changed when the restore is performed by applying each delta image, with reference to the cost information of applying delta.
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Citations
20 Claims
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1. An image restore method executed in a storage system comprising:
- a disk array storage system comprising a disk drive in which a primary volume used by a server for some purpose is set from/to which data is read and written, a block device interface that sends and receives data and control signals to/from a computer, a disk interface that sends and receives data and control signals to/from with the disk drive, a memory that stores a control program, and a CPU that executes the control program to control input and output of the data to/from the disk drive; and
a backup management device that manages backup and restore of the data stored in the disk array storage system using a full backup image obtained by copying a whole of the data stored in the primary volume at a predetermined timing and each delta image obtained by copying a data changed after one of the full backup and delta backup,the image restore method comprising;
creating a temporary restored image by applying each required delta image to the full backup image and storing the temporary restored image in a restore destination volume;
judging whether the reverse delta image and a cost table of applying delta relating to each applied the delta image have been created, with each reverse delta image recording the reverse delta image before the application of the applied delta image and the cost table of applying delta recording a number of blocks of the applied delta image;
creating, if the reverse delta image and the cost table of applying delta relating to the applied delta image are not yet created, the reverse delta image related to the applied delta image and recording a number of delta application blocks relating to the applied delta image in the cost table of applying delta;
judging whether an intended restore target has been restored with reference to a backup creation date and time recorded in a delta backup management table;
recording, if it is judged that the intended restore target has been restored, a backup date and time of the restore target; and
creating, if it is not judged that the intended restore target has been restored, a new temporary restored image, calculating a sum of a number of blocks of each reverse delta image that should be applied to the temporary restored image in order to reach the intended restore target with reference to the cost table of applying delta, and obtaining a number of blocks that is changed when restore is performed by applying the reverse delta image;
calculating a sum of a number of blocks of the full backup image and a total number of blocks of each delta image that should be applied to the full backup image in order to reach the intended restore target with reference to the cost table of applying delta, and obtaining a number of blocks that is changed when the restore is performed by applying the delta image;
comparing the number of blocks that is changed when the restore is performed by applying the reverse delta image with the number of blocks that is changed when the restore is performed by applying the delta image;
performing the restore by applying the reverse delta image that is necessary in order to reach an intended restore target, to the temporary restored image if the restore through the application of the reverse delta image results in a fewer number of blocks to be changed; and
performing the restore by sequentially applying the delta image that is necessary in order to reach an intended restore target, to the full backup image if the restore through the application of the delta image results in a fewer number of blocks to be changed.
- a disk array storage system comprising a disk drive in which a primary volume used by a server for some purpose is set from/to which data is read and written, a block device interface that sends and receives data and control signals to/from a computer, a disk interface that sends and receives data and control signals to/from with the disk drive, a memory that stores a control program, and a CPU that executes the control program to control input and output of the data to/from the disk drive; and
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2. A storage management device comprising:
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a control unit that manages backup and restore of data stored in a storage device using a full backup image obtained by copying a whole of the data stored in the storage device at a predetermined timing and each delta image obtained by copying a data changed after one of the full backup and delta backup, wherein the control unit creates a temporary restored image by applying each required delta image to the full backup image, creates a reverse delta image before the application of the delta image, records a number of delta application blocks relating to the applied delta image as cost information of applying delta, and determines a restore method by comparing a number of blocks, which is changed when restore is performed by applying each piece of the reverse delta image that is necessary in order to reach an intended restore target, with a number of blocks, which is changed when the restore is performed by applying each delta image that is necessary in order to reach the intended restore target, with referring to the cost information of applying delta. - View Dependent Claims (3, 4, 5, 6)
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7. An image restore method executed in a storage management device comprising a control unit that manages backup and restore of data stored in a storage device using a full backup image obtained by copying a whole of the data stored in the storage device at a predetermined timing and each delta image obtained by copying a data change made after one of the full backup and delta backup,
the image restore method comprising: -
creating a temporary restored image by applying each required delta image to the full backup image;
creating a reverse delta image before the application of the delta image;
recording a number of delta application blocks relating to the applied delta image in cost information of applying delta;
calculating a number of blocks, which is changed when restore is performed by applying each piece of the reverse delta image, and a number of blocks, which is changed when the restore is performed by applying each. delta image, with referring to the cost information of applying delta;
comparing the number of blocks, which is changed when the restore is performed by applying the piece of the reverse delta image, with the number of blocks, which is changed when the restore is performed by applying the delta image, and determining a restore method on basis of a result of the comparison; and
performing the restore using the determined method. - View Dependent Claims (8, 9, 10, 11)
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12. A computer program product for managing a storage device by a storage management device,
wherein the storage management device comprising a control unit that manages backup and restore of data stored in the storage device using a full backup image obtained by copying a whole of the data stored in the storage device at a predetermined timing and each delta image obtained by copying a data change made after one of the full backup and delta backup, the program controlling the storage management device to: -
create a temporary restored image by applying each required delta image to the full backup image;
create a reverse delta image before the application of the delta image;
record a number of delta application blocks relating to the applied delta image in cost information of applying delta;
calculate a number of blocks, which is changed when restore is performed by applying each piece of the reverse delta image, and a number of blocks, which is changed when the restore is performed by applying each delta image, with referring to the cost information of applying delta;
determine a restore method by comparing the number of blocks, which is changed when the restore is performed by applying the piece of the reverse delta image, with the number of blocks, which is changed when the restore is performed by applying the delta image; and
perform the restore using the determined method. - View Dependent Claims (13, 14, 15, 16)
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17. A storage system. comprising:
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a storage device comprising a disk drive in which a primary volume is set from/to which data is read and written, a block device interface that sends and receives data and control signals to/from a computer, a disk interface that sends and receives data and control signals to/from the disk drive, a CPU that executes a control program to control input and output of the data to/from the disk drive, and a memory that stores the control program; and
a storage management device comprising a control unit that manages backup and restore of the data stored in the storage device using a full backup image obtained by copying a whole of the data stored in the storage device at a predetermined timing and each delta image obtained by copying a data changed after one of the full backup and delta backup, wherein the control unit of the storage management device. creates a temporary restored image by applying each required delta image to the full backup image, creates a reverse delta image before the application of the delta image, records a number of delta application blocks relating to the applied delta image as cost information of applying delta, and determines a restore method by comparing a number of blocks, which is changed when restore is performed by applying each piece of the reverse delta image, with a number of blocks, which is changed when the restore is performed by applying each delta image, with referring to the cost information of applying delta. - View Dependent Claims (18, 19, 20)
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Specification