From Microsoft point of view, records in CRM should be deactivated rather than copied to another location and deleted from the source. Reason being, the CRM database can operate efficiently for a long time with a growing database.
Check out the blog on the following link. The author talks about a few options and gives pros and cons for each.
http://salimadamoncrm.com/2013/01/04/microsoft-dynamics-crm-data-archiving/
Jason Peterson