Despite being potentially the most expensive part of your HTPC setup, storage is also the most straight-forward to set-up and maintain. The need is pretty basic – put some files somewhere an application can access them – and is something people have been doing since the stone age. However, beyond that things get murkier. In order to shine a light, you will need to first figure out how you plan on handling your media. HTPC users tend to gravitate towards three general preferences when it comes to content: the streamer, the recycler and the hoarder. There are advantages and disadvantages to each, and where you come down is largely a matter of preference. However, this preference has obvious implications for your storage needs, which in turn has other important downstream effects.
If you are a streamer, you really don’t need much in the way of storage; just enough to run your software and some caching. The Raspberry Pi Quick-Start Guide recommends a 8Gb SD card to run NOOBS and most Kodi-for-Pi sources recommend up to 32GB as example. You will however want something that has very good read/write speeds; flash memory or the aforementioned SD cards (at least the higher classes) will do fine.
Recyclers have it easy and can use whatever’s available. Need more space? Delete some stuff.
If you’re a hoarder, you’ve got some more questions to answer, primarily “how much money does this hobby mean to you?” You don’t have to drop a lot of cash to be a hoarder, but if you really want an extensive collection of your 800 favorite movies and every episode of Dr. Who in crystal clear HD, throwing cash at the problem does make things a whole lot easier.
The first option you have is to store everything on your “main” machine and stream it over your local network; a free and easy, if limiting, solution. Unless you’re an old fuddy-duddy desktop guy like me, you’ll fill up your laptop’s drive with 1080p content in a snap, and external drives eat up valuable ports and shackle down your otherwise portable laptop. Another problem with using your main computer this way is that it needs to be up whenever you want to watch content. This is just an inconvenience if you inadvertently put it to sleep before heading into the bedroom for some late-night Parks and Rec, but it’s salt in the wound if a motherboard failure now takes out your TV in addition to your laptop.
Storage local to your HTPC is also very easy; you will need some way to get content over to it, but once it’s there you don’t need to worry about much else. USB drives work well here, since it insulates the content data against any issues on the HTPC’s local drive and the only limitation to your capacity is the number of ports and the size of your drives. The caveats with this approach are the lack of data protection and a potential performance hit if you use Plex or another transcoding-based platform (particularly if you use USB 2.0).
The third option is setting up some kind of network-attached storage; a stable and separate device dedicated to storage and serving content over the local area network. If you’re looking to establish a long-term HTPC solution, this is probably where you’ll end up. It’s another device to manage, but it gives your setup maximum flexibility, longevity, and (depending on your hardware and configuration options) some protection against hardware failure. The resources required to stream or even transcode media are not terribly high (Plex recommends a 2.4GHz Core 2 Duo or more for a single 1080p transcode), so if you have a 2006+ machine lying around, you could slap some drives into it and make a competent media server. Alternatively, there are a growing number of companies making purpose-build NAS devices for the small-business\home market, and although they are a bit more expensive pound-for-pound when compared to a home-built machine I prefer them for one big reason: RAID. Most of the purpose-built devices support all sorts of RAID arrays, including some proprietary levels which give you handy extra features; for instance, Synology’s SHR allows you to use the additional space in a mixed-size disk array and handles hardware changes much more nimbly than regular RAID in my experience.
I wanted a simple way to protect and share my rather large library, so I went with a Synology 411J. Its four bays gives me a ton of storage space and the hybrid RAID allowed me to easily expand my volume as I could afford additional drives; I also find that having a single folder for all of a specific type of content makes managing my library much easier in Kodi. However, I only got there after trying out a bunch of options and figuring out what I really cared about, and what I was willing to do in order to achieve it. You may start out as a hoarder and then give up your worldly content in favor of a simpler streaming lifestyle (or the other way around), so I would encourage you to start simple and\or cheap and then work your way up. Most of the purpose-built NAS devices are fairly expensive and come “empty” (without hard drives), so I wouldn’t encourage you to leap immediately to that solution.