Methods, systems, and computer program products for processing read requests received during a protected restore operation
AssigneeEMC Corporation
InventorsDavid Haase, Somnath A. Gulve, Saurabh M. Pathak
Life of this patent
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Abstract
According to one aspect, the subject matter described herein includes a method for processing read requests received during a restore operation, where a protected restore operation includes copying at least a portion of the data content of the clone to its source. The method includes receiving a read request to read data from a source during a protected restore operation. It is determined whether to redirect the read request to the clone, and in response to determining to redirect the read request to the clone, the read request is redirected to read data from the clone.
Claims17
A method for processing read requests received during a protected restore operation, the method comprising:
- in a data storage system having a first portion of data denominated as a source and at least a second portion of data denominated as a clone, wherein the clone receives data from the source through synchronous mirroring until fracturing occurs after which the clone has data content that is a point-in-time copy of data content of the source and during a protected restore operation that includes copying at least a portion of the data content of the clone to the source, wherein during the protected restore operation the data content of the clone is prevented from being modified:
- receiving a read request to read data from the source;
- determining whether to redirect the read request to the clone, wherein determining whether to redirect the read request to the clone includes determining whether the read request requests data that has yet to be copied from the clone to the source;
- and
- in response to determining to redirect the read request to the clone, redirecting the read request to read the data from the clone via a stack on the clone, wherein data is read from the source for a subsequent read request during the protected restore operation.
A system for processing read requests received during a protected restore operation, the system comprising:
- a data storage system comprising one or more physical data storage devices, the data storage system including a first portion of data denominated as a source and a second portion of data denominated as a clone, wherein the clone receives data from the source through synchronous mirroring until fracturing occurs after which the clone has data content that is a point-in-time copy of data content of the source;
- and
- a read request manager for receiving a read request to read data from the source, for determining whether to redirect the read request to the clone, wherein determining whether to redirect the read request to the clone includes determining whether the read request requests data that has yet to be copied from the clone to the source and, in response to determining to redirect the read request to the clone, for redirecting the read request to read data from the clone via a stack on the clone during a protected restore operation, wherein data is read from the source for a subsequent read request during the protected restore operation, wherein during the protected restore operation the data content of the clone is prevented from being modified.
A computer program product comprising computer executable instructions embodied in a non-transitory computer readable medium for performing steps comprising:
- in a data storage system having a first portion of data denominated as a source and at least a second portion of data denominated as a clone, wherein the clone receives data from the source through synchronous mirroring until fracturing occurs after which the clone has data content that is a point-in-time copy of data content of the source and during a protected restore operation that includes copying at least a portion of the data content of the clone to the source, wherein during the protected restore operation the data content of the clone is prevented from being modified:
- receiving a read request to read data from the source;
- determining whether to redirect the read request to the clone, wherein determining whether to redirect the read request to the clone includes determining whether the read request requests data that has yet to be copied from the clone to the source;
- and
- in response to determining to redirect the read request to the clone, redirecting the read request to read the data from the clone via a stack on the clone, wherein data is read from the source for a subsequent read request during the protected restore operation.
Dependencies are inferred from the claim text.