Two ways that immediately come to mind. The first is to get a NAS device. I use a Synology. If your wireless router has a USB port on it that supports drives, you can just use that.
The upside to going with a NAS device that is compatible with Logitech's server software is that you won't need to have a computer on all of the time. The downside is that they are relatively expensive. If you go with a NAS device, be sure that it meets system requirements. A speedy processor is good and at least 256mb of memory.
