For taking Backup of CMS or BO system there are two ways1) Replicate the Source environment using Import wizard to other system(test/dev/backup)2) Using CCM take the backup of CMS database and also File system
If you use copy datasource option, you also have option and advantage of copying the source cms db to any other db like Oracle, mySQL, MSSQL, Sybase.(irrespective of what is the source db)cheers!Ankur.