Switching roles between a production storage device and a snapshot device
First Claim
1. A computer implemented method for improving performance of storage device operations, the method comprising the steps of:
- switching roles of an underlying production storage device and a created snapshot device, such that the production storage device is used as the snapshot device and the snapshot device is used as the production storage device, by performing, by a computer, at least one of the following modifications to input/output requests to the production storage device and to the created snapshot device;
responsive to receiving a request to write new content to the production storage device, modifying the received write request by
1) copying affected old content from the production storage device to the snapshot device, and
2) writing the new content to the snapshot device instead of to the production storage device;
responsive to receiving a request to read content from the snapshot device, modifying the received read request by reading the content from the production storage device instead of to the snapshot device; and
responsive to receiving a request to write new content to the snapshot device, modifying the received write request by
1) copying affected old content from the production storage device to the snapshot device, and
2) writing the new content to the production storage device instead of to the snapshot device.
8 Assignments
0 Petitions
Accused Products
Abstract
A snapshot manager switches the roles of a production storage device and a corresponding snapshot device by modifying read and write requests to the devices. Thus, translation mapping information concerning the acting snapshot device does not change, so a remote computing device can perform a backup from the acting snapshot without having to restart every time content is written to the production device. After the backup operation, the snapshot manager can update the underlying data source from the acting production device to capture writes to production that occurred during the backup. The snapshot manager then reverts the roles of the storage device and the snapshot to normal.
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Citations
20 Claims
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1. A computer implemented method for improving performance of storage device operations, the method comprising the steps of:
switching roles of an underlying production storage device and a created snapshot device, such that the production storage device is used as the snapshot device and the snapshot device is used as the production storage device, by performing, by a computer, at least one of the following modifications to input/output requests to the production storage device and to the created snapshot device; responsive to receiving a request to write new content to the production storage device, modifying the received write request by
1) copying affected old content from the production storage device to the snapshot device, and
2) writing the new content to the snapshot device instead of to the production storage device;responsive to receiving a request to read content from the snapshot device, modifying the received read request by reading the content from the production storage device instead of to the snapshot device; and responsive to receiving a request to write new content to the snapshot device, modifying the received write request by
1) copying affected old content from the production storage device to the snapshot device, and
2) writing the new content to the production storage device instead of to the snapshot device.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. At least one computer readable storage medium containing a computer program product for improving performance of storage device operations, the computer program product comprising:
program code for switching roles of an underlying production storage device and a created snapshot, such that the production storage device is used as the snapshot and the snapshot is used as the production storage device, by treating input/output requests to the production storage device and the created snapshot as follows; responsive to receiving a request to write new content to the production storage device, modifying the received write request by
1) copying affected old content from the production storage device to the snapshot, and
2) writing the new content to the snapshot instead of to the production storage device;responsive to receiving a request to read content from the snapshot, modifying the received read request by reading the content from the production storage device instead of to the snapshot; and responsive to receiving a request to write new content to the snapshot, modifying the received write request by
1) copying affected old content from the production storage device to the snapshot, and
2) writing the new content to the production storage device instead of to the snapshot.- View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A computer system for improving performance of storage device operations, the computer system comprising:
a portion configured to switch roles of an underlying production storage device and a created snapshot, such that the production storage device is used as the snapshot and the snapshot is used as the production storage device, by treating input/output requests to the production storage device and the created snapshot as follows; responsive to receiving a request to write new content to the production storage device, modifying the received write request by
1) copying affected old content from the production storage device to the snapshot, and
2) writing the new content to the snapshot instead of to the production storage device;responsive to receiving a request to read content from the snapshot, modifying the received read request by reading the content from the production storage device instead of to the snapshot; and responsive to receiving a request to write new content to the snapshot, modifying the received write request by
1) copying affected old content from the production storage device to the snapshot, and
2) writing the new content to the production storage device instead of to the snapshot.- View Dependent Claims (18, 19, 20)
Specification