I have been searching for a raid card that works for m.2 drives. I need this as I desire redundancy for my datastore in Esxi. I have bought the Asrock Rack ROMED8-2T for use with the Epyc 7343. The <a href="https://www.supermicro.com/en/products/accessories/addon/AOC-SLG4-2H8M2.php">AOC-SLG4-2H8M2</a> looks like exactly what I want with esxi compatibility, but it mentions that it only works with Supermicro boards. Does anyone have experience with Supermicro AOC that knows if that is just a suggestion or if it really won’t work in another board? Seems like it’s a standard Raid controller on the board. Or has anyone found a solution to m.2 raid now? I have done some searching and only found other people that switched to proxmox - I have some other esxi servers and have a pro license so I’d like to keep it standard if at all possible.
Actually, after making the post, looks like I might have found a card. It at least claims VMware compatibility on Amazon. It’s only pcie3.0 though, but I will take it unless anyone else has pcie4.0 cards they know of. HighPoint-Technologies-SSD6202A-Controller-Virtualization
Welcome!
I don’t have first hand experience but I’d be truly surprised if it only worked with supermicro motherboards. Supermicro as a company isn’t in the habit of making artificial limitations on it’s products.
I’m pretty suspicious of the Highpoint products because they advertise most as hardware raid but almost none of them are.
Another option to consider is Areca, they make m.2 hardware raid cards in DRAM-less (they call these “entry level”) and DRAM variants:
Broadcom Tri-Mode card and U.2 to M.2 NVMe adapters should work.
I appreciate your response! I hadn’t seen the Areca cards, but they look like a good option, although slightly pricey. Since you commented that they don’t have a habit about limitations and the Supermicro is only a few hundred I have ordered it instead. I will report back with my findings and probably go with Areca if that card isn’t compatible.
I originally went with the high point and the main thing I noticed is there are some that actually say “VMware” in the supported OS and they have a hardware switch, like this one did to be able to set raid 1. The problem is that it didn’t come with the right bracket and I’m building in a 2U chasis, so I’m not really sure how well it would have worked as I didn’t end up using it but seems like it would have been compatible.
Another option is to setup a linux NFS / iSCSI target. Then you can use ZFS or software RAID, and as a bonus shared storage for fast live migration. You could even run it as a VM on ESXi, passthrough the NVME SSDs, and point NFS / iSCSI at the VM … crazy but it’d work.
Definitely not a bad idea, and I’m setting up lots of storage on 12Gb sas drives too for shared storage. The main issue is that I want a redundant datastore in esxi for piece of mind as I’m building a server to co-locate several hours away so I’m trying to make it as redundant as possible so it can wait a week or two for me to run whatever fix I need out to Atlanta. I also know ssd’s typically fail in different ways than traditional hard drives so most people don’t bother with raid, but it makes me feel warm and fuzzy inside 
The ironic part is that from my experience SSD tend to fail less gracefully than HDDs and would benefit more from RAID, but I suppose RAID isn’t implemented on SSDs as often because it drags down performance.
Okay, so I finally got all my hardware cooperating and the Supermicro card works! I was able to configure a raid 1 in the bios and install ESXi on that. Thanks for the input, I’ve learned a good bit about nvme raid cards along the way.