The problem with a USB drive plugged into a hub is that the hub itself needs to translate this into a network drive. As mentioned before not all the hubs/routers/modems facilitate this, and your testing seems to have ruled this option out for your particular situation. You could of course buy another modem/router to fix this but if you're going down that route, you might as well buy a NAS instead.
The more I think about it, the more I see this as a fitting option. I think that you have two options:
- Buy enough cloud storage to accommodate all your data. Apple's iCloud is a good option for this but Dropbox might work too. The downside of this solution is that it takes quite a while to upload 500 Gb and you're very dependent on the whims and pricing policy of the service provider. A plus is that your data is available everywhere as long as you've got internet access.
- Buy a NAS, which is basically a (very) small PC in a housing that allows you to fit one or more hard drives, and which can be linked to a network. Get one with two drives so that you can have one drive as a backup to the other (can be done automatically). On the plus side, this is a one time investment and copying speeds are only limited by your network. Downside could be that files are only available within your own network but some NAS devices allow you to setup a server that can be found from everywhere on the internet. You will need to get a small app for your iPad such as FileExplorer to browse through the files on the NAS. An app like this may be available from the NAS builders itself, and you shouldn't need any other apps to get this working. Initial costs to get a NAS are higher than for the cloud solution but once it is up and running, you don't have any other costs other than replacing it after say 10 years or so.
Good luck with the project!
