Your NV+ is a bit old and I agree that it might be the time to get a replacement. If you plan to upgrade your unit any ReadyNAS OS 6 4 Bay unit or up will be fit for you.
Your disks and data can be migrated to these OS 6 units but in some cases it will be needing Data recovery service from NETGEAR Support.
RN424 or RN524 might be a good choice as a replacement and since your NV+ is still running you can still use it for backup.
Your disks and data can be migrated to these OS 6 units but in some cases it will be needing Data recovery service from NETGEAR Support.
Actually the data can't be migrated, the title of that KB article is misleading. The disks can be temporarily mounted in the OS 6 system, but you then need to off-load the data to other storage. After that you set up the new NAS, which reformats the disks and destroys all the data on them. This service is really to help out folks with failed NAS - in your case the NV+ is working, so you don't need it.
Personally I'd start off the replacement with new disks - fewer but larger ones, and leave some empty slots for growth later on. For instance, 2x6TB. Then continue to use the NV+ to back up the OS 6 NAS as long as it lasts.
