You already know about the OWC Thunderblade option. Basically, you're talking about a DAS (direct-attached storage) option hooked to a Mac Mini.
The amount of storage you are after suggests to me you will be going with HDD rather than SSD-based storage, unless you can handily afford that amount of SSD storage (20 terabytes in the next 10 months, + redundancy, and room to expand from there). The UGreen 4800 Plus, I believe, holds 4 HDDs but has 2 slots for SSDs which can be used as read/write cache to speed things up. This matters because you've got to factor in how slow HDDs are, how fast the data transfer speed is between your device and your computer, and what you want to do with it.
You can search YouTube for 'Use Mac Mini as a NAS' and get some hits. Here's one:
I have some questions about how such a system works out in the real world.
1.) It may be fine for backing up your MacMini and others Apple devices (e.g.: Macs, iPhones, an iPad?), but how do you backup a Windows notebook, desktop or Android device to it? A lot of people have a Windows work notebook, or a Windows gaming PC, etc. I would anticipate that a NAS would be more platform agnostic. Will you set up user accounts on this device? If you use your MacMini with a big attached RAID box for storage, can someone with a Windows notebook effectively make use of a user account on it? I don't know, I'm just raising the question.
2.) Do you know how to access those Eufy security cameras from it, like you mentioned? I would think this would work, but better check.
3.) Do you intend to use RAID 5 (requires at least 3 discs, 1 can fail without losing data) or RAID 6 (requires as least 4 discs, up to 2 can fail without losing data), and will you backup the RAID to a different device? RAID offers redundancy but people often claim 'RAID is not a backup!' (which is arguable, but if the device fails, or something makes too many discs fail at once, well...).
4.) How valuable is your content, and will you back it up to another device? This sounds like a rehash of 3.), but I focus on the question because you wanted an 8-bay DAS unit. Okay, but are you factoring in discs lost to provide RAID redundancy? With RAID 5, your 8-bay unit is a 7-bay unit; with RAID 6, it's a 6-bay unit.
5.) How much money are you ready to pour into this? An
8-bay OWC ThunderBay 8 runs around $850 direct. But read the description carefully; SoftRAID is $150 extra! You can use Apple RAID free, but Google
Apple RAID vs SoftRAID and see the differences; A couple of notes from the description:
-----Despite being a Thunderbolt 4 device, the data transfer speed is noted at up to 2,586 MG/s, note that superscript 1 footnote indicator, and drop to the very bottom of the page. "Sequential read/write performance with 8 x 2.0TB Mercury Extreme Pro 6G SSD in RAID 0 connected to iMac Pro Late 2017 (iMacPro1,1) with 32GB RAM and 3.2GHz processor running AJA System Test (4K-Full resolution, 64GB file size, 10bit RGB codec, single file test)."
SSDs. Find out how the transfer speed would be with HDDs. It may sound nice that it supports SSDs, but note: "8 bays supporting: 2.5-inch SATA HDDs, 2.5-inch SATA SSDs, 3.5-inch SATA HDDs, 3.5-inch SATA SSDs" You might compare size, cost and speed of SATA vs. NVME SSDs. Just something to be aware of.
-----"daisy-chain up to five additional ThunderBay 8 or other Thunderbolt storage devices via the second Thunderbolt port."
This I like. You can easily (not cheaply) expand your storage.
6.) Where will you keep this and what is your tolerance for noise? SSDs are silent; HDDs make noise, that spin up racket, the occasional 'click,' etc. If you envision having this thing sitting on the desktop in front of you
with 8 of them beside a MacMini, how loud will it be? Maybe not a big deal, but maybe do some checking.
7.) The OWC ThunderBay 8 doesn't note RAID 6 in its list of RAID options.That a problem? Would be for me, with as many drives as you want to use.
8.) It's got ThunderBolt 4, which is very nice! But I don't see mention of Ethernet. ThunderBolt cables are far more expensive and you can practically get far longer Ethernet cables; I've got a 75 foot Cat. 8 flat white ethernet cable from the living room router running along the wall baseboard with sticky clips, around a door frame and into my computer room. Ethernet gives you nice options.
9.) You have to make your own choices, of course. I wouldn't do this. If you hook your spare M4 MacMini with 10 Gig ethernet (yet you use a 2011 MacMini while the M4 is spare?) to a DAS, and this isn't your main rig., what do you gain?
On sale direct, $300, nearly $1,200 can get you
a UGREEN NASync DXP8800 Plus. Dual ThunderBolt 4 ports and "
Dual 10GbE Network Ports: Two 10GbE high-speed network ports that can be aggregated into 20G bandwidth for download speeds of up to 2500MB/s." 8 Bays + 2 M.2 NVMe bays. Supports RAID 6 (amongst other options).
From reviews I've seen, I might think about bumping the RAM from 8 to 16 gig. Some headroom for the future, depending on what you do with it.
10.) I've seen recommendations to use a UPS for a NAS since the RAID might suffer during an abrupt power outage; UGreen sells one for this purpose, but there are others. It's nice if the device can get a signal from the UPS and power itself down before the battery is exhausted; I don't know whether you can set a MacMini and/or ThunderBay to do that or not.
11.) In your cost appraisal, don't forget that HDDs and SSDs have limited life expectancies. It's not entirely 'buy once, cry once.' When that rig (whether a ThunderBlade or a NAS RAID setup) gets maybe 8 years old or so, you might get nervous... By then, maybe 30 gig Seagate Iron Wolf HDDs will be cheap!
12.) Be aware Ubiquity is coming out with
an 8-bay NAS at roughly $800, but the reviews of the older 7 bay version suggest it's mainly a NAS and doesn't have as much server functionality as some competing NAS offerings do. It's my understanding that at this time you can't run Plex on it. But the Ubiquity offerings are seen as an excellent value if you want that many bays and you're mainly about NAS not server functionality. You mentioned a rack mount form factor; I think the UNAS 8 can do that.
I'm curious about NAS and I've been researching the subject in hopes of someday getting one; I hope you'll keep posting in this thread as you learn more about NAS and DAS options, as what you uncover might be useful to me.
