The best way I have come up with is downloading the underlying data of maps manually off Portal, uploading them to the new Portal, then loading the Maps from the old Portal in Pro, switching the layer's data sources to the new Portal and then publishing the map to the new portal. Does anyone have a better solution?
As for why manually and not with Python, the clone_items method doesn't actually work and just creates useless references to the original item.
There isn't a one-size-fits-all solution. However, if you are running ArcGIS Enterprise 10.8.1, you can leverage this:
Hi LR2,
Please take a look at this video from Day 3 of the Esri Dev Summit Plenary. It demos content deployment automation.
Content Deployment Automation video
Hope this helps,
Agree. No single answer. I use ArcGIS On Line Assistant 1st. Then pick up the content I can't move with ArcGIS On Line Assistant other ways.