I've just migrated with D7 installation from the dev server into production one (backup&migrate module used).
After migration I can see all three users (admin, manager and tester). The admin account on prod serv was created during the installation keeping the same details (the DB name, user, pass - the same for both intallations).
Both servers are Debian Apache PHP 5.3 VPSes
Now, on the production server I can see all content and generally the page works, except some administrative issues.
1. I can't log in using 'manager' or 'tester' account.
2. I can't create a new user.
3. I can't delete existing user.
4. I can't setup roles(permissions) -> after update old settings are back.
5. I can't get any email with a new password (forgotten pass)
6. I can't switch off any module (only way is to delete them manually from the server)
so generally it looks like the 'read only' version of admin panel.