Changing between the states of Replicator Log protection
To enable Replicator Log protection you can set the srlprot attribute to any one of the modes: fail, override, DCM, or AutoDCM. Volume Replicator allows transition between the srlprot values, but there are some situations when the transitions between the states do not succeed.
Note: |
When the DCM logging is enabled as part of Replicator Log protection mechanism, changing to the Fail or Override mode is disallowed. |
The following table highlights the valid state transitions when the Secondary (RLINK) is connected.
Table: Valid state transitions with Secondary RLINK connected
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Changing Replicator Log Protection (srlprot) > From
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Changing Replicator Log Protection (srlprot) > To |
Outcome of the original state |
Result after state transition |
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Fail
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AutoDCM
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The writes are correctly throttled, until the Replicator Log is freed of some space.
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Changing the mode from Fail to AutoDCM cannot guarantee that the DCM logging is enabled.
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Override
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AutoDCM
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The writes are correctly throttled, until the Replicator Log is freed of some space.
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Changing the mode from override to AutoDCM cannot guarantee that the DCM logging is enabled.
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DCM
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AutoDCM
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The writes are correctly throttled, until the Replicator Log is freed of some space.
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Changing the mode from DCM to AutoDCM cannot guarantee that the DCM logging is enabled.
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AutoDCM
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DCM
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The DCM logging is enabled.
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Since the DCM logging is already enabled, the RLINK (Secondary) is not disconnected.
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The following table highlights the valid state transitions when the RLINK (Secondary) is disconnected.
Table: Replication State Transitions when Secondary RLINK is disconnected
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Changing Replicator Log Protection (srlprot) > From
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Changing Replicator Log Protection (srlprot) > To |
Outcome of the original state |
Result after state transition |
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Fail
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AutoDCM
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Results in an error to the application for the current write.
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The DCM logging is enabled on the next Input/Output operation by the application.
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Override
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AutoDCM
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The Replicator Log Overflows.
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The DCM logging is not used since the Replicator Log has already overflowed and replication is stopped. The replication must be started to the Secondary using the Automatic Synchronization operation.
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DCM
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AutoDCM
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The DCM logging is enabled.
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The DCM logging is already enabled.
Secondary must be made up-to-date by using the resynchronization operation.
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AutoDCM
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DCM
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The DCM logging is enabled.
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The DCM logging is already enabled.
Secondary must be made up-to-date by using the resynchronization operation.
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