Hi Didier, there is no "single click" to add an existing DMA (or DMS) into an existing DMS.

It's more that you have to be very much aware that the DMA which is being added to the cluster will lose information.

It works like this: The cluster always contains the master data. So when you first start with a brand-new cluster, the DMA that has been added to the cluster first (time is important here), contains the master data. Any subsequent DMA that is added to this cluster might drop its own data for the data in the cluster.

Some examples:

• There is only one view tree structure in a DMS, so a DMA that is added to the cluster will drop its view structure and all elements will be under the root. Same for security.xml and many other things.
• Protocols are being merged, meaning that the protocols that don't exist yet in the DMS but exist on the DMA you are adding, will be added to the DMS. Same for e.g. documents.
• Production version remains the version of the DMS, which might be different from the DMA you are adding...
• Etc.

In other words, you would need to choose which DMA of the 2 contains the most important data, put this one in the cluster first, then add the second DMA, and that one would lose information you would need to clean up or fix again. If you want to avoid this, you'll need to manually check quite some items. E.g. merge view structure into a single file, verify they are running the same protocol (versions), verify the templates (alarm & trending), verify automation scripts, ... so be very cautious with this action.

Having a backup is of vital importance here, so that you can still get things from the backup.