I'd love to find a M2-only NAS in a very low profile form factor. I live in a small apartment and prefer small electronics that can hide in a cabinet, but it seems like all of the NAS enclosures that I've ever seen recommended are fucking huge.
QNAP has at least two "NASbooks":
https://www.qnap.com/en-us/product/tbs-464 (2.5 GbE, USB 3.2)
https://www.qnap.com/en-us/product/tbs-h574tx (2.5/10 GbE, Thunderbolt 4)
https://wiki.friendlyelec.com/wiki/index.php/CM3588_NAS_Kit
there is also the asustor nas: https://www.asustor.com/de/product?p_id=80
If you just need a single nvme SSD you could also buy a banana pi 3 Router:
https://wiki.banana-pi.org/Banana_Pi_BPI-R3
Edit: forgot links and product
Unfortunately Synology have been moving towards Enterprise segment and completely forgot consumer.
This would give 3 M.2 slots and high speed ethernet.
https://www.amazon.com/dp/B07N1HC88M
Something like this can be used to upgrade a dual-3.5" SATA NAS into a 8x-M.2 NAS (assuming the cooling and everything work appropriately).
Just some ideas.
Pros:
- It does what it says on the tin and I have 12 nvme drives in a ZFS pool
- It has 10G ethernet built in.
- It's pretty small, especially compared to most HDD focused NAS systems.
- It's just an x86 PC and you can blast the factory OS away to install your OS of choice without issue.
Cons:
- Each drive only gets a 3.0 x1 connection. It's honestly not much of a problem though as 1 GB/s per drive is still a ton of bandwidth after 12 drives.
- The built in ethernet is RJ45 instead of SFP+. Not the end of the world, just less power efficient.
- No PCIe expansion slots for anything but m.2 2280 drives.
- Single RAM slot so no dual channel and no large amounts of RAM. 32 GB works fine (I think Intel says the processor is only rated for 16). I can't remember if I tried 48 and it failed or if I never bothered. Either way 32 GB can be a bit small if you're really wanting to load it up with 4 TB or 8 TB drives and features like ZFS deduplication.
- The single built in fan could have been silent had they made any reasonable design choice around it. Instead I had to externally mount a noctua fan (to the same screw holes, just the inside is not a standard mount) and feed it power via a USB adapter. Works damn silent and cool now though.
- CPU (4 core Intel Celeron N5105) is very weak and the actual performance limitation for most any setup with this box.
I don't regret getting it, it's a solid choice given the relative lack of premade options in this segment, but the follow up NAS build was just me getting a motherboard/CPU with lots of PCIe lanes and loading up 4 way switches. You can do that via buying used Epyc servers on Ebay (loud/chunky) or just building a low end consumer class "workstation" (things like x8 x8 from the CPU instead of x16 for the assumed GPU) and PCIe to x4 switches (not the splitter cards which assume the motherboard has bifurcation and lanes available but actual switches). If you go the Epyc route you don't have to get switches and you can go back to cheaper splitters. I went the latter via some PCIe switch cards off Aliexpress. Performance and scaling of this one was better of course, but so was cost. Since I did all of this prices for m.2 drives have actually went up quite a bit so I'm glad I did it when I did.
What I would not recommend is anything non-x86 (older Ampere servers have lanes at not sky high prices but better to just go used Epyc at that point and get more CPU perf for the same dollar. SBCs are... a poor choice for a NAS on most every account but hacking factor). I'd also not recommend the Flashstor 6 as it only has 2.5 GBe connectivity and at that point what's the value in paying extra to do this all in flash.
You can get m.2 adapters: https://www.delock.com/produkt/64219/dokumente.html?d=467
Side note: One of the m2 chips that I got from Amazon was an obvious fake that I might not have caught if I hadn't ordered four together and one obviously didn't match.