I am migrating a Sharepoint 2013 domain from company A to company B (all on premise installations). Company B also has their own Sharepoint 2013 environment, but completely separate and independent inftrastucture. No A/D trust between systems, although the A/D accounts from domain A have been recreated in company B; obviously not exactly the same but the corresponding accounts from the old company have been mapped to new/similar account names in company B.
Right now my plan is to stage a single server farm in the destination domain of Company B to host Company A's Sharepoint farm. Create the new farm, restore the content database(s), etc. Get that all working with the accounts and permissions and then migrate that to their current 2013 farm (or if not possible then maybe stop there and just expand the farm to the typical multi-server farm setup).
What is the best way to bring forward the SharePoint Farm from Company A into Company B? Since we don't have a domain trust, I'm not sure how to proceed with handling the permissions and how to map users between systems. I can get a spreadsheet with an export of A/D info from the Source domain, but not sure how to go about mapping that (or if it is possible) to map that to their equivalent new accounts in SharePoint -- and handle the permissions as well.
What would be the best way to essentially export permissions from the source per user account and then bring that forward into the migrated sharepoint environment at the destination?