SharePoint 2007 to 2010 migration failed at 1% due to insufficient permission

Details:

All agents have the required permission, but migration fails at 1% with the error:

Please check if the user has the Database Owner permission for database.

Cause:

The Agent Account in SharePoint 2010 needs to have db_owner permission, but if the account also has SharePoint_Shell_Access permission, the db_owner permission may have been granted through PowerShell, and the permission change is not detected.

Solution:

1. Deselect the SharePoint_Shell_Access permission for the affected Agent Account in SQL logins.
2. Navigate to SP_Portal_01 database > Security > Users > the affected Agent Account.
3. Manually grant db_owner and SharePoint_Shell_Access permissions to the Agent Account.
4. Go back to SQL logins and confirm the SharePoint_Shell_Access permission selected again.

*Note: If a large number of content databases are affected, please contact AvePoint Technical Support and reference this KB Article ID.