Slow Replication During Differential Sync

During a differential synchronization operation, the rate at which a replication pair generates the protection files might slow down or stop after you have remapped a source or target LUN.

Error Received

One of the following errors occurs:

Data mode: Differentials reach to appliance and continue to progress. There is no impact on pair progress.
Metadata or bitmap modes: S2 is not able to read source LUN, because of LUN Unmap.
Target is not able to apply the differentials/resync files.

Symptoms

One or more of the following symptoms might be present:

Resynchronization operation is not progressing: RPO is increasing.
The number of replication files during differential synchronization is increasing.
No communication from the source LUN to the Oracle MaxRep Replication Engine exists because the differential throttle delay and resynchronization is not progressing.

Resolution

One of the following resolutions apply:

Map the source LUN to the Replication Engine.
Map the target LUN to the Replication Engine.