Start by taking a snapshot or backup of your existing server. This process is non-invasive on the original server, but better safe than sorry. Since you can do this with the server running, you can do a test run and then do it again, turning off the original server, making sure you have the latest data.
Second, please archive your logs. This greatly reduces the size of the database and prevents issues during an upgrade. Go to Logs > Archive logs on the WiKIDAdmin.
Start on the existing server. Export the data with WiKID running:
# su - postgres
$ pg_dumpall -p 5432 > wikid.backup
(Or 5434 if you are using replicaton.)
Configure the new server and start it to make sure everything is working. You can create new certs or move your old ones over (they are in /opt/WiKID/private). Everything else is in the database and will be over-written by the imported data. Stop WiKID.
Copy the wikid.backup file to your new server.
scp wikid.backup root@new_server_ip:~
Note that postgres's home directory is /var/lib/psgql.
cp /root/wikid.backup /var/lib/pgsql/
chown postgres:postgres /var/lib/pgsql/wikid.backup
Start the database:
# service postgresql start
# su - postgres
Drop the existing db:
$ dropdb 'wikid'
Import the old one:
$ psql -f wikid.backup
Stop Postgresql so we can be sure the database schema is updated:
service postgresql stop
Then, remove this file:
Now, start WiKID. You should see 'Applying cumulative schema updates ...' on restart.
Check that all your users have moved. Also, browse to Configuraton, Enable Protocol Modules and make sure that you see the Active Directory protocol.