Application level backup
See Domain Backup guide.
Database level backup
There are three fundamentally different approaches to backing up PostgreSQL data:
File system level backup
Each has its own strengths and weaknesses; each is discussed on the PostgreSQL documentation pages.
All settings, meta-data and raw data are stored within the PostgreSQL database server. Database backup is sufficient to preserve the entire BellaDati application.
The most common is the SQL dump, which backups the database contents using the dump command:
pg_dump -U user -p port -F c -v -f "path_to_dump/dump.backup" belladati_db
Copy the backup file to your new system and restore it in the target database:
pg_restore -v -c -O -d belladati_db -U user -p port path_to_dump/dump.backup