Q: External Hard Drives Showing Up as Internal using Hub

have you asked over at Targus since it's their product?

http://targus.com/us/support

yes i encounter exact same issue its an elcapitan issue, as its a non issue on yosemite. pity my mbpr came with elcapitan

NOTE: i tried two different brand hubs

if u write to them they should fix it, if many of us complain,

here is the link

http://www.apple.com/feedback/

i wrote to targus and they got back to me saying

Hi Sharon,

Thank you for your enquiry, unfortunately the answer is no.. the ACH124 model was manufactured before the release of the El Capitan operating system, which we have not released any new driver for since. At the moment there are no plans for Targus to release a new driver for the El Capitan.

Apologies for not being able to help you on this occasion Sharon.

Kind Regards,

Nathan

so there you go, its the hubs not the os like i thought.