Testing replica data using modifiable cloned images
Creating a modifiable cloned image of a dataset, including: generating, based on a dataset stored within a source data repository, a tracking copy of replica data on a target data repository; generating, after receiving an indication to begin accepting modifications to the tracking copy of the replica data, a cloned image of the dataset that is modifiable without modifying the tracking copy of the replica data; and responsive to a storage operation directed to the target data repository, modifying the cloned image of the dataset without modifying the tracking copy of the replica data.
1 . A method comprising:
making available a clone, on a target data repository, of a tracking copy of replica data, wherein the tracking copy maintains updates to the replica data that are received from a source data repository; and
based on an instruction to modify the tracking copy, applying one or more modifications to the clone instead of applying the one or more modifications to the tracking copy.
2 . The method of claim 1 further comprising making the clone available in response to a promotion event promoting the tracking copy, wherein the promotion event includes a detected failure, an impending failure, a detected change in performance, or a user-initiated promotion event.
3 . The method of claim 1 , wherein making the clone available further comprises generating a point-in-time image of the tracking copy.
4 . The method of claim 3 , wherein the point-in-time image represents one or more updates to the replica data that are described in one or more lightweight checkpoints.
5 . The method of claim 1 , wherein metadata describing one or more updates to a dataset at the source data repository references content identifiers on the respective source data repository and target data repository, wherein the content identifiers are a basis for avoiding transfer of data based on identifying content on the target data repository that is the same as content on the source data repository, and wherein content is identified as being the same based on sharing a common definition for respective content identifiers on the source data repository and the target data repository.
6 . The method of claim 5 , wherein metadata describing one or more updates to the dataset includes one or more ordered checkpoints that specify the one or more updates to the dataset.
7 . The method of claim 6 , wherein a quantity of updates described by a given checkpoint depend on a configurable data replication setting.
8 . The method of claim 6 , further comprising receiving, at the target data repository from the source data repository and independent from receiving metadata including the one or more checkpoints describing the one or more updates to the dataset, data corresponding to the one or more updates to the dataset.
9 . The method of claim 8 , wherein generating the tracking copy of replica data on the target data repository includes applying, in order, the one or more updates corresponding to the data received from the source data repository.
10 . The method of claim 1 wherein the clone is modifiable without modifying the tracking copy of the replica data.
11 . A storage system that includes a computer memory and a computer processor, the computer memory including program instructions that, when executed by the computer processor, cause the storage system to carry out the steps of:
making available a clone, on a target data repository, of a tracking copy of replica data, wherein the tracking copy maintains updates to the replica data that are received from a source data repository; and
based on an instruction to modify the tracking copy, applying one or more modifications to the clone instead of applying the one or more modifications to the tracking copy.
12 . The storage system of claim 11 , further comprising computer program instructions that, when executed by the computer processor, carry out the step of making the clone available in response to a promotion event promoting the tracking copy, wherein the promotion event includes a detected failure, an impending failure, a detected change in performance, or a user-initiated promotion event.
13 . The storage system of claim 11 , wherein a replica link specifying a replica configuration changes direction of data replication from the target data repository to the source data repository.
14 . The storage system of claim 11 , wherein a snapshot of the clone is created that describes modifications made to the clone by one or more storage operations directed to the target data repository from a host computing device.
15 . The storage system of claim 11 , wherein metadata describing one or more updates to a dataset at the source data repository references content identifiers on the respective source data repository and target data repository, wherein the content identifiers are a basis avoiding transfer of data based on identifying content on the target data repository that is the same as content on the source data repository, and wherein content is identified as being the same based on sharing a common definition for respective content identifiers on the source data repository and the target data repository.
16 . The storage system of claim 15 , wherein the program instructions, when executed by the computer processor, further cause the storage system to carry out the steps of receiving, at the target data repository from the source data repository and independent from receiving metadata including checkpoints describing one or more updates to the dataset, data corresponding to the one or more updates to the dataset.
17 . The storage system of claim 11 , wherein generating the tracking copy of replica data on the target data repository includes applying, in order, one or more updates corresponding to data received from the source data repository.
18 . The storage system of claim 15 , wherein metadata describing one or more updates to the dataset at the source data repository includes one or more ordered checkpoints that specify the one or more updates to the dataset.
19 . The storage system of claim 18 , wherein a quantity of updates described by a given checkpoint depend on a configurable data replication setting.
20 . A computer program product disposed on a non-transitory computer readable medium, wherein the computer program product includes computer program instructions that, when executed, carry out the steps of:
making available a clone, on a target data repository, of a tracking copy of replica data, wherein the tracking copy maintains updates to the replica data that are received from a source data repository; and
based on an instruction to modify the tracking copy, applying one or more modifications to the clone instead of applying the one or more modifications to the tracking copy.