SSRS Domain Migration My company is currently going through a data center migration.  We are now down to the SQL Servers and this includes SSRS.  The bad thing that is going to hit us is the current SSRS server is being migrated to a new domain.  So all users/groups that have access to SSRS are in DomainA and after the migration the SSRS server will be in DomainB.

All user and groups were migrated from DomainA to DomainB, supposidly using the preserve SIDs.  During a test we could not get this to work.

So DomainA\User1 does not work when server is changed to DomainB.

We have over 70,000 combinations of user permissions and group permissions across all of our reports.

Does anyone have any suggestions or ideas on how we can properly migrate this server from DomainA to DomainB without having to manually duplicate the security settings.

Note:  This is a virtual machine and is being replicated from one VMWare cluster to one on the new network and then will be dis-joined from DomainA and joined to DomainB.  Service accounts will be changed to DomainB and backup of encryption key will be restored after service account is changed.
I would go back to testing and find out why the SID migration did not work. It is a migration Microsoft supports with Active Directory. I would suggest engaging the support for the Data Center you are moving to for assistance. (or even Microsoft...)

If the SIDs cannot be fixed your only option is going to be recreating the accounts and permissions. Thinking about it, since Data Center moves could be in your future again (or at least the companies) you might rethink some of those permissions where all of it is groups, even if you are dealing with one account currently.

You can execute queries against the ReportServer instance to get those permissions, but not one to modify the logins and such.