I have installed Owncloud 9.0.3 on my Raspberry Pi 3 running Debian. I added an external USB drive and mounted it as /media/NASDRIVE and I can write to it but I can not get owncloud to see it. I added it as an external drive after downloading the app and set it up as NASDRIVE and used the id - 503ECC223ECC02C8 but if I click on it it just returns to the root. If I try to set it up on the intial wizard it says it failed to write to it. I am not sure what to do but seems like some sort of permissions issue?
Sounds like a Linux issue, not an ownCloud issue. When you can mount it in Linux correctly, ownCloud can work with the file system ...
I would disagree because I can access it fine in Linux but ownCloud can not access it so it is some sort of permissions issue with ownCloud that is missing.
Accessing on command line (probably also with a different user) is something completely different then accessing it from PHP. Have a look at the following FAQ for every info you need how to configure your PHP environment (and so ownCloud) to access external storages with the correct permissions: