I have an iMac that sits on a desk attached to a Time Capsule, which acts as my wireless router. Can I attach an external hard drive to the iMac (not the TC) and make it a sort of network server? In other words, I have a bunch of Macs, iPads, iPhones, etc. and want them all to be able to access an external hard drive attached to the iMac for iTunes, iPhoto, etc. with the iMac being able to be backed up with Time Capsule. If not possible, any suggestions? Thanks.