Building a Home Server or Network Attached Storage system (NAS) to secure your backups and act as a home cinema / TV media server is simpler than you might think. Chances are you already have an old computer that can be used - and so long as you have no more than 10 other computers / multimedia boxes that need to access the Server 'at the same time', there is no need to pay Microsoft for an actual 'Windows Server' level operating system.
If you need more than 10 simultaneous connections, to avoid the need to pay for and install Microsoft 'Server' operating system (and pay for the required number of Client Access Licences) or learn how to use some flavour of the Open Source LINUX Operating System (which is very easy to use as a file backup or 'share', but exceedingly difficult to use as a DLNA Media Server), you can separate the file store (NAS) from the DLNA (media server) functions (and run them on a separate box).
Why build your own NAS ? Well, anyone who has looked into buying a NAS / 'Cloud Server' on Amazon and checked out the '1 star' and '2 star' customer reviews will soon realise what a minefield buying a NAS is.
I never waste my time with the 5 star reviews as they are either un-informative 'It works fine' reviews (from happy real customers) or pages of lies and marketing hype from the Vendors 'shrills'.
First, these days, you won't find an (affordable) NAS that runs 'Windows'. So (assuming your other computers are running Windows) software 'compatibility' is a major issue. Almost every NAS is built on Linux and the low end kit uses ONLY Linux drive 'formats' and directory structures - this means anyone foolish enough to plug in an existing Windows drive will soon find it being automatically 'wiped', at a rate of 1Tb per day (if you are lucky). Some low end NAS systems are even incapable of handling file sizes over 2Gb (or drives over 2Tb).
Next, if you think Windows is hard to use, you should try setting up the average NAS vendors system ! The number of 'bugs' in the average NAS system software will cause you continuous frustration, whilst guaranteeing your data will be dropped down a 'black hole' on the first incorrect parameter choice (yes, the average NAS really can be set-up in a 'write only' configuration !).
Then, even if you are lucky to find a NAS that formats it's drives in 'standard' NTFS, chances are, should that NAS fail, moving the NAS drive into your PC (or some other vendors NAS) still won't get your data back. Plus, whilst a single drive fail on a RAID 1 (mirror) would not normally be a disaster, some low end NAS systems refuse to allow you access as soon as one drive fails. Some even lack 'rebuild RAID mirror' functionality = instead they may automatically wipe the remaining working drive when you replace the failed one !
Of course there will always an issue with speed ... or, rather, the lack of. Whilst many NAS boxes come with 'Gigabit Ethernet' they 'drop back' to 100 mbs when actually transferring data ! Not that this matters since they never achieve transfers speeds of anything like 100 mbs. In fact, 5 to 15 mbs is a typical 'back-up' speed, which is about 2 days per Tb == and this from SATA 3 hard drives supporting 6000 mbs !
Then there's the 'Indexing Service' ran by many NAS boxes. Todays NAS software programmers have learnt nothing from the 'bad old days' of Windows and it's tendency to 'lock up' whilst 'Indexing' your drive - and that was with drives of a few hundred Mb's ! Yes = some NAS boxes will literally take HOURS re-indexing every time you add another file !
Many NAS boxes come with 'clever' back-up utilities that will find specific file types 'automatically'. However if you make the mistake of allowing these to run, be prepared to wait for a few days after first turning on your nice new NAS whilst the NAS utilities 'lock up' your PC searching for, and backing up, a few Tb of your photos / music / video files
Needless to say, every NAS comes with lots of 'extra' functions (remote Internet access, 'Cloud' operation, DLNA / media streaming etc etc). These will all default to 'no password' and 'root access' and present you with massive security holes (even harder to understand and configure than Windows 'services'). This more or less guarantees that all your data will be made available to anyone in the world who happens to stumble across your IP address
Finally, there's "what to do when you need more space". If you think you can 'swap out' one of the existing mirror drives with a much larger replacement, you are likely to be disappointed - the NAS firmware will have been coded for today's drive sizes, so when you buy a NAS box that says 'supports up to 2x 3Tb drives' don't imagine that it will work with 2x 4Tb. Of course, if you are lucky, and can replace a failed 3Tb with a 4Tb, the NAS will format it down to 3Tb, with no way to 'expand' the size up again (other than swap out both 3Tb drives and starting again). By the time you can afford 2x 6Tb chances are the manufacturer will have moved onto 'bigger and better' boxes, so no more support, ever ..
So, if you want to keep you data safe, secure and accessible, with a 'future proof' and repairable NAS, 'read on' (click Next>>, bottom left) and 'build your own' !