1. Tar the old BB directory
tar cvjf bb.tbz phpBB2
(Replace phpBB2 with the name of the folder containing your earlier phpBB2 installation)
2. Get the data from the mysql table
mysqldump -u root -p --databases div_dbase > div.sql
(replace 'root' with any other admin name who has full permission and 'div_dbase' with the name of database used by your old installation)
3. Scp these files to your new machine.
(It is expected that you have mysql, php-mysql, apache etc are installed and turned on in the new machine)
4. re-insert the sql data
mysql -u root -p < div.sql
Note 1: If you are a mysql pro and want to take some trouble configuring a new user at your old machine who can access mysql db on the old machine from the new one, this step might not be needed
Note 2: The mysql that comes with F11 does not consider --- as a comment. However the old sql dump will have a line like -------------. Just edit it and make it -- --------------- (Note the space after two hyphens).
5. Untar the old BB2 installation folder into /var/www/html. Rename if necessary (You may want to use the same folder name for BB3)
6. Download and install BB3
7. Make the directories of BB3 owned by apache user
chown -R apache.apache forum
(Where 'forum' is the folder containing the BB3 installation)
8. Click on the convert tab. Enter necessary information. Assuming you followed step 4, you will have to enter: new root password, location of old BB2 wrt to new BB3 (If you were strictly sticking to these instructions, it will be ../
Thats it. Just click the convert button and you will have the new BB ready in a few minutes!