Consider the following scenario:
- In Microsoft System Center 2016, you have a primary Data Protection Manager (DPM) server (DPM1) to protect the data resources.
- You have a secondary DPM server (DPM2) to protect DPM1.
- You try to use DPM2 to back up a deduplicated volume that's protected by DPM1.
In this scenario, you receive the following error message:
The DPM service was unable to communicate with the protection agent.
This behavior is by design. After a deduplicated file system is protected by a primary DPM server, it is no longer supported to be protected by a secondary DPM server. For more information, see Deduplication issues.