In our terms upgrade between Parallels Plesk Billing (formerly known as Modernbill) v4 and Parallels Plesk Billing v6 is called migration.
To know more about how to prepare your system for migration, you may use the following article: http://kb.sp.parallels.com/en/5305
Basically you need to do the following:
- you need to create fresh (empty) mysql database and new mysql user for v6
- perform v6 installation with this new database, using the following documentation: http://download.ppb.parallels.com/6.0/doc/parallels-plesk-billing-6.0-for-linux-installation-update-guide/17509.htm
- once you have installed v6 go to lib-billing/include/config/config.php in v6, and find 'MIGRATION SETTINGS' section and there should be 2 config variables
$CONF["syncMigrationIDs"] = true;
you need to change this to
$CONF["syncMigrationIDs"] = false;
- now you log in to v6 and go to System -> System Settings -> Add Migration.
- here you can select that you want to do migration from Modernbill v4 and specify connection to v4 mysql database.
- then you follow migration wizard that will guide you through client/package/modules section.
Also please check http://pleskbilling.com/support/manual/old/v5co.pdf (starting at page 16)