I've discovered a bug which causes you to lose the ability to login as the admin user. I discovered it in the Windows version. Here's how to duplicate (and fix) the bug.
1. Set-up Openfire using the Embedded Database.
2. Create a second user and grant that user admin privileges.
3. Change the Server Name.
4. Restart the Server.
You will no longer be able to login to your server using any login.
You have two options to fix the bug.
First, STOP the server.
Second, edit this file:
/openfire/embedded-db/openfire.script
Third, do either of the following:
1. Remove the lines that read:
INSERT INTO OFPROPERTY VALUES('admin.authorizedJIDs','admin@SERVERNAME,seconduser@SERVERNAME')
2. Alternatively,you'll notice on the line above that SERVERNAME is your OLD Serve Name. Change what appears in SERVERNAME from the older Sever Name to the NEW Server Name. Save.
Fourth, Restart the server.
If you do #1, all users who were designataed as administrators will lose their admin status. You will be able to login only using the "admin" user.
If you do #2, all users will retain admin status and be able to login again.