I follow the steps here to upgrade a 2007 SSP database to 2010:
After the upgrade everything appears successful and users can see their My Links from 2007. However, shortly after this all the My Links are deleted. This corresponds with SharePoint sending out emails like this:
The My Site of Joe Blow is scheduled for deletion in 14 days....
Which I've learned is a result of SharePoint's auto site deletion when a user owns a site and is no longer in the system. I'm assuming the My Links deletion is part of this process as well. Furthermore, the rows in the UserProfile table went from thousands to less than 100.
I believe the issue is there are only 91 profiles synced out of the thousands that exist. why are only a small subset of the profiles syncing?