System and method for dynamically resynchronizing backup data
First Claim
1. A method of resynchronizing data contained in a data storage system having primary and backup storage sites both coupled to a data mover, the primary storage site coupled to a host that provides write data to the primary storage site, the data mover serving to mirror data stored at the primary storage site upon the backup storage site, where during predetermined error conditions the data mover stores data received by the storage system in the primary storage site without mirroring the data to the backup storage site, the method comprising:
- after termination of an error condition, the data mover performing a static resynchronization process comprising;
identifying data received during the error condition at the primary storage site without mirroring to the backup storage site;
reading the identified data from the primary storage site at one or more read times;
writing the read data to the backup storage site; and
the primary storage site receiving update data from the host for storage while no error condition is occurring, the update data representing changes to data already existing on the primary storage site, and in response;
the data mover determining whether the static resynchronization process is in progress, and if not, copying the update data to the backup storage site;
if the static resynchronization process is in progress, the data mover determining whether the static resynchronization process is already processing data corresponding to the existing data, and if not, copying the update data to the backup storage site;
if the static resynchronization process is already processing data corresponding to the existing data, the data mover copying the update data to the backup storage site only if the host provided the update data to the primary storage site after the static resynchronization read time for the data already being processed.
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Accused Products
Abstract
Backup storage is resynchronized to primary storage, ensuring that any new updates received during resynchronization are applied in the proper order relative to resynchronization data. Under normal operations, a data mover mirrors data stored in primary storage to backup storage. If an error condition arises, preventing mirroring, the data mover stores newly received data in primary storage without mirroring the data to backup storage. The data mover also identifies this data in an update map. When the error condition ends, the data mover performs a static resynchronization process, serving to update the backup storage with the un-mirrored data, identified in the update map. When new data is received during static resynchronization, a dynamic resynchronization process is invoked to accurately process the updates. Dynamic resynchronization ensures that newly received data records are copied to backup storage in the proper order (if at all) with respect to versions of the same data being processed by static resynchronization.
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Citations
18 Claims
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1. A method of resynchronizing data contained in a data storage system having primary and backup storage sites both coupled to a data mover, the primary storage site coupled to a host that provides write data to the primary storage site, the data mover serving to mirror data stored at the primary storage site upon the backup storage site, where during predetermined error conditions the data mover stores data received by the storage system in the primary storage site without mirroring the data to the backup storage site, the method comprising:
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after termination of an error condition, the data mover performing a static resynchronization process comprising;
identifying data received during the error condition at the primary storage site without mirroring to the backup storage site;
reading the identified data from the primary storage site at one or more read times;
writing the read data to the backup storage site; and
the primary storage site receiving update data from the host for storage while no error condition is occurring, the update data representing changes to data already existing on the primary storage site, and in response;
the data mover determining whether the static resynchronization process is in progress, and if not, copying the update data to the backup storage site;
if the static resynchronization process is in progress, the data mover determining whether the static resynchronization process is already processing data corresponding to the existing data, and if not, copying the update data to the backup storage site;
if the static resynchronization process is already processing data corresponding to the existing data, the data mover copying the update data to the backup storage site only if the host provided the update data to the primary storage site after the static resynchronization read time for the data already being processed. - View Dependent Claims (2, 3, 4, 5)
the data mover configures an update map to identify data received by the storage system in the primary storage site without mirroring the data to the backup storage site due to a predetermined error condition;
the identifying of the data received during the error condition at the primary storage site without mirroring to the backup storage site comprises consulting the update map; and
the determining of whether the static resynchronization process is already processing data corresponding to the existing data comprises the data mover determining whether the update data is identified in the update map.
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3. The method of claim 1, where:
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the reading of the identified data from the primary storage site at one or more read times further includes;
repeatedly reading groups of the identified data until all identified data has been read; and
for each group of read data, storing indicia representing the read data in a progress queue along with a time of the reading.
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4. The method of claim 1, where:
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the static resynchronization process further comprises setting a static resynchronization indicator; and
the determining of whether the static resynchronization process is in progress comprises determining whether the static resynchronization indicator is set.
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5. The method of claim 1, where the primary storage site and backup storage site include disk storage media and the primary storage site receives update data as records comprising subparts of a tracks.
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6. A method of resynchronizing data contained in a data storage system having primary and backup storage sites both coupled to a data mover, the primary storage site coupled to a host that provides write data to the primary storage site, the data mover serving to mirror data stored at the primary storage site upon the backup storage site, where during predetermined error conditions the data mover stores data received by the storage system in the primary storage site without mirroring the data to the backup storage site, the method comprising:
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after termination of an error condition, the data mover performing a static resynchronization process comprising;
identifying data received during the error condition at the primary storage site without mirroring to the backup storage site;
reading the identified data from the primary storage site at one or more read times;
writing the read data to the backup storage site; and
responsive to the primary storage site receiving update data from the host while the static resynchronization process in progress, the update data representing changes to data already existing on the primary storage site, the data mover determining whether the static resynchronization process is already processing data corresponding to the existing data, and if so, the data mover copying the update data to the backup storage site only if the host provided the update data to the primary storage site after the static resynchronization read time for the data already being processed.
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7. A data storage system, comprising:
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a primary digital data storage site, coupled to a host that provides write data to the primary storage site;
a backup digital data storage site;
a data mover coupled to the primary storage, backup storage, the data mover being programmed to mirror data stored at the primary storage site upon the backup storage site, where during predetermined error conditions the data mover stores data received by the storage system in the primary storage site without mirroring the data to the backup storage site, the data mover also being programmed to perform a method to resynchronize data of the backup data storage site with data of the primary data storage site comprising;
after termination of an error condition, the data mover performing a static resynchronization process comprising;
identifying data received during the error condition at the primary storage site without mirroring to the backup storage site;
reading the identified data from the primary storage site at one or more read times;
writing the read data to the backup storage site; and
the primary storage site receiving update data from the host for storage while no error condition is occurring, the update data representing changes to data already existing on the primary storage site, and in response;
the data mover determining whether the static resynchronization process is in progress, and if not, copying the update data to the backup storage site;
if the static resynchronization process is in progress, the data mover determining whether the static resynchronization process is already processing data corresponding to the existing data, and if not, copying the update data to the backup storage site;
if the static resynchronization process is already processing data corresponding to the existing data, the data mover copying the update data to the backup storage site only if the host provided the update data to the primary storage site after the static resynchronization read time for the data already being processed. - View Dependent Claims (8, 9, 10, 11)
the system further includes an update map accessible by the data mover;
the data mover is further programmed to configure the update map to identify data received by the storage system in the primary storage site without mirroring the data to the backup storage site due to a predetermined error condition;
the identifying of the data received during the error condition at the primary storage site without mirroring to the backup storage site comprises consulting the update map; and
the determining of whether the static resynchronization process is already processing data corresponding to the existing data comprises the data mover determining whether the update data is identified in the update map.
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9. The system of claim 7, where:
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the reading of the identified data from the primary storage site at one or more read times further includes;
repeatedly reading groups of the identified data until all identified data has been read; and
for each group of read data, storing indicia representing the read data in a progress queue along with a time of the reading.
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10. The system of claim 7, where:
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the static resynchronization process further comprises setting a static resynchronization indicator; and
the determining of whether the static resynchronization process is in progress comprises determining whether the static resynchronization indicator is set.
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11. The system of claim 7, where the primary storage site and backup storage site include disk storage media and the primary storage site receives update data as records comprising subparts of a tracks a subpart of a track.
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12. A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing machine to perform a method of resynchronizing data contained in a data storage system having primary and backup storage sites both coupled to a data mover, the primary storage site coupled to a host that provides write data to the primary storage site, the data mover serving to mirror data stored at the primary storage site upon the backup storage site, where during predetermined error conditions the data mover stores data received by the storage system in the primary storage site without mirroring the data to the backup storage site, the method comprising:
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after termination of an error condition, the data mover performing a static resynchronization process comprising;
identifying data received during the error condition at the primary storage site without mirroring to the backup storage site;
reading the identified data from the primary storage site at one or more read times;
writing the read data to the backup storage site; and
the primary storage site receiving update data from the host for storage while no error condition is occurring, the update data representing changes to data already existing on the primary storage site, and in response;
the data mover determining whether the static resynchronization process is in progress, and if not, copying the update data to the backup storage site;
if the static resynchronization process is in progress, the data mover determining whether the static resynchronization process is already processing data corresponding to the existing data, and if not, copying the update data to the backup storage site;
if the static resynchronization process is already processing data corresponding to the existing data, the data mover copying the update data to the backup storage site only if the host provided the update data to the primary storage site after the static resynchronization read time for the data already being processed. - View Dependent Claims (13, 14, 15, 16)
the data mover configures an update map to identify data received by the storage system in the primary storage site without mirroring the data to the backup storage site due to a predetermined error condition;
the identifying of the data received during the error condition at the primary storage site without mirroring to the backup storage site comprises consulting the update map; and
the determining of whether the static resynchronization process is already processing data corresponding to the existing data comprises the data mover determining whether the update data is identified in the update map.
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14. The medium of claim 12, where:
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the reading of the identified data from the primary storage site at one or more read times further includes;
repeatedly reading groups of the identified data until all identified data has been read; and
for each group of read data, storing indicia representing the read data in a progress queue along with a time of the reading.
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15. The medium of claim 12, where:
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the static resynchronization process further comprises setting a static resynchronization indicator; and
the determining of whether the static resynchronization process is in progress comprises determining whether the static resynchronization indicator is set.
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16. The medium of claim 12, where the primary storage site and backup storage site include disk storage media and the primary storage site receives update data as records comprising subparts of a tracks.
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17. A data storage system, comprising components of:
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primary and backup storage sites, the primary storage site coupled to a host providing write data to the primary storage site;
a data mover coupled to the primary and secondary backup storage sites, and programmed to perform operations comprising;
mirroring data stored at the primary storage site upon the backup storage site;
during predetermined error conditions, storing data received in the primary storage site without mirroring the data to the backup storage site;
resynchronization operations comprising;
after termination of an error condition, the data mover performing a static resynchronization process comprising;
identifying data received during the error condition at the primary storage site without mirroring to the backup storage site;
reading the identified data from the primary storage site at one or more read times;
writing the read data to the backup storage site; and
responsive to the primary storage site receiving update data from the host while the static resynchronization process in progress, the update data representing changes to data already existing on the primary storage site, the data mover determining whether the static resynchronization process is already processing data corresponding to the existing data, and if so, the data mover copying the update data to the backup storage site only if the host provided the update data to the primary storage site after the static resynchronization read time for the data already being processed.
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18. A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing machine to perform a method of resynchronizing data contained in a data storage system having primary and backup storage sites both coupled to a data mover, the primary storage site coupled to a host that provides write data to the primary storage site, the data mover serving to mirror data stored at the primary storage site upon the backup storage site, where during predetermined error conditions the data mover stores data received by the storage system in the primary storage site without mirroring the data to the backup storage site, the method comprising:
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after termination of an error condition, the data mover performing a static resynchronization process comprising;
identifying data received during the error condition at the primary storage site without mirroring to the backup storage site;
reading the identified data from the primary storage site at one or more read times;
writing the read data to the backup storage site; and
responsive to the primary storage site receiving update data from the host while the static resynchronization process in progress, the update data representing changes to data already existing on the primary storage site, the data mover determining whether the static resynchronization process is already processing data corresponding to the existing data, and if so, the data mover copying the update data to the backup storage site only if the host provided the update data to the primary storage site after the static resynchronization read time for the data already being processed.
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Specification