Duo V2 to NV+ upgrade

If a lot of your data volume is in videos (they really eat the space) and they are not that critical (not family movies for example), then you only concentrate on the critical/important data. For example, while I have a 2.5TB data volume, only about 70GB of mine falls into that category. Personal financial records and photos that are not replicated elsewhere (except in my backups). In addition the NAS to NAS backup of all my shares, only the shares with critical/important data is then also backed up onto a WD passport and stored offsite. I do this periodically, but usually at least once a month. This is my fallback if a disaster befalls the house and wipes out my NAS units as well. (Fire, theft, natural disaster).