External USB Hard Drive as personal cloud

Hi all,
I’ve done some digging around in the SUSE forums but not found anything specific.
Has anyone successfully set up an external USB hard drive as a personal cloud?
If so, how?
I’ve got a 5 TB USB HD laying around and so I don’t want to spring for a Western Digital box if I don’t have to.
With 4 computers used as pleasure and work boxes and also having to
use that other “pain in the (gl)ass” operating system for some apps for which there are no Linux distro’s avaiable
like a PIC micro-controller software compiler and a schematic capture and PC board auto-router.
Instead of just using the USB HD to do back-ups it would be nice to be able to have everything available anywhere
I have a wifi socket.

There is owncloud?

But it would required it installed on one system, your home router doesn’t have a USB port for storage?