Would Like Some Input On DIY NAS Idea.

[JDMyers]

So to preface my question, I have an older PC that I have for all intents and purposes decommissioned for the past year and a half. Slowly fazing out my old system over 6 months till I ended up with an entirely new gaming PC and leaving the older one to sit and collect dust so far. I have over the past year and a half also come into possession of my friend's and family's old laptops because "I'm techy and would probably have a use for them". Now I don't have a whole lot of use for 3 of the laptops so I would at the very least like to recycle the HDD's and install them into my old PC to make a home NAS solution. I already have a WD My Cloud but it is a Gen 1 I picked up on clearance a few years ago, mainly for the 2TB HDD included that in total only cost me $40. I would ultimately like to Install the 3 laptop drives and 2TB WD drive into the old PC and make it the NAS.

Old PC Specs (Please don't judge my build lol I built this at 17 with my own money back in 2011 with a budget of about $500)

WIFI Network Card:

Rosewill RNX-N250PC2 - Wireless N300 Wi-Fi Adapter - IEEE 802.11b/11g/11n, (2T2R), Up to 300 Mbps Data Rates, PCI ...

 

CASE:

AZZA Toledo 301 (CSAZ-301) Black SECC Steel ATX Mid Tower Computer Case

RAM: 

G.SKILL Value Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model F3-10666CL9D-8GBNT

PSU: 

RAIDMAX Scorpio series RX-535AP-S 535W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS BRONZE Certified Modular Power ...

CPU:

AMD Phenom II X4 965 Black Edition Deneb Quad-Core 3.4 GHz Socket AM3 125W HDZ965FBGMBOX Processor

Motherboard:

ASRock 970DE3/U3S3 AM3+ AMD 770 + SB710 SATA 6Gb/s USB 3.0 ATX AMD Motherboard

Original OS SSD:

SanDisk ReadyCache SDSSDRC-032G-G26 2.5" 32GB SATA III for Windows 7 and Windows 8 -based PCs

GPU: 

EVGA GeForce GTX 670 DirectX 11 02G-P4-2670-KR 2GB 256-Bit GDDR5 PCI Express 3.0 x16 HDCP Ready SLI Support Video Card

The laptop and NAS drives:
1 WD 2TB
1 Toshiba 500GB
1 Toshiba 320GB
1 WD 160GB (I don't NEED this one to be a part of the storage)

So questions time.
1: I assume this is possible but if not let me know now.

2: What Software or OS should I get to run the entire system on?
3: Do I NEED any additional hardware?
4. I have a lot of files stored on the 2TB drive, will I need to move those to another location during the process?

Criteria I would like to be met.

1. Work primarily as a NAS, as long term media storage to be accessed about 4-5 times a week.
2. Run PLEX.
3. Hopefully view all drives as one partition, or at least the 3 smaller drives. 
4. I would like it to require as little maintenance as possible. 
5. If it won't work better then the current My Cloud I have then I would rather not bother. By work better I mean just in general have more functionality and be very hassle free after setup. 

I am an avid watcher of LTT on YouTube and I tried to do a search on the channel for videos that might tackle this exact situation but after a few minutes I decided to give the Forum a shot for the first time. I have an okay amount of PC knowledge but admittedly am lacking in this area. If anyone needs more information to help me out I will do my best to facilitate. I'm not looking for you all to do every bit of work for me but just help me out with putting together a solution that fits my needs based on other's experiences. Hope this post doesn't sound too demanding  Thank you in advance for any help.

[WereCatf]

10 minutes ago, JDMyers said:

Hopefully view all drives as one partition, or at least the 3 smaller drives.

I think only Unraid would work for that. Anything else I can think of, like e.g. plain old JBOD, have too many downsides to them that I wouldn't recommend them. The thing is, combining a bunch of disks of different sizes is a mess and there aren't many clean solutions for that. (I do use Btrfs for it, but I have a whole lot more drives than you. In e.g. Btrfs RAID5 you can have drives of different sizes, but the two biggest drives must be of the same size for it to work.)

[Salacious B Crum]

Your hardware is fine for what you want to do, I am partial to unRAID but its cheap for what you get I would set you system up and start the 30 day free option with unRAID it is not locked down meaning you will have all available options as a person who purchased it if you are working it through its paces they may even offer you a 30 day extension its web UI is great if your not command line literate like me

[JDMyers]

So I completely forgot to put this in the points at the bottom of the post. I would like to explore any free options first if they exist. Now that I think about it the "view as one large partition" bit is much less of a request. I will look into the UnRaid free trial though thank you both for your responses so far.

[Jarsky]

If you want to pool the storage, you could look at something like Rockstor or a RAID over FS solution like FlexRAID. 

If you just want to run them as individual disks, then really any OS you feel comfortable with is going to be fine. 

The hardware looks perfectly fine for a basic NAS though. 

[Salacious B Crum]

13 hours ago, JDMyers said:

So I completely forgot to put this in the points at the bottom of the post. I would like to explore any free options first if they exist. Now that I think about it the "view as one large partition" bit is much less of a request. I will look into the UnRaid free trial though thank you both for your responses so far.

Well then mediavault is free and I found to be a bit easier to setup than say freeNAS so you may give that a shot it is also light weight but it runs docker so there are plenty of options there including plex