I have two PCs on my home network, each with 3 HDDs. I have a ton of pictures from my amateur sports photography hobby and family photos on both PCs and need to think about backing them up. I have a Linksys router with a USB storage port I could use but trying to find the easiest and cost effective way to back up both PCs. Should I partition a large external HDD then used the USB port on the router or would the more extensive NAS be the solution?