In the front of the servers you can place 3 M.2 NVMe's, via those convertor prints Hyve has developed, to convert from U.2 to M.2. But, I rather just plug in U.2 devices directly. Those are faster and then I can use 4 devices instead of 3. The issue is that you have to get those devices attached some how, which is hard because of all the M.2 stuff. But you can easily remove it. Just 4 screws and then you can remove the top plate. Then just pull up a pin and then you can remove the bottom plate. And then I had a 3D holder designed, for 4 U.2! And I'm sharing this file now with all of you, so you can print this holder yourself, if you want to. I have permission from the actual designer to do so.
This holder can hold 4 NVMe's, both 7 and 15mm thick. And it slides over the pins the bottom plate was attached to as well, and then it is in place.
The 15mm thick NVMe's you should place in the lowest screwholes, and the 3rd one from the bottom. The 7mm thick NVMe's should be placed in the second and forth screwhole from the bottom. Otherwise you will hit a bump in the chassis and the connector won't fit.
Don't print this in PLA, because the inside of the server can become too hot for it. Use PETG.
I have tested this print on a Bambu Labs P1S and it printed fine.
I hope this helps somebody!