Hello.

I would like your opinion regarding a hardware configuration and my Openstack cluster project.

I have the possibility of purchasing 6 servers to build this cluster for students, my current Openstack being too small.

I have a proposition from the manufacturer (DELL): 6 servers with characteristics per server:

- BOSS-N1 controller card + with 2 M.2 960GB (RAID 1)

- 5 x 3.84TB Data Center NVMe Read Intensive AG Drive U2 Gen4 with Carrier

- 12 x 64GB RDIMM, 4800MT/s Dual Rank

My problem is: BOSS is used to install the system (Ubuntu 22.04 in my case).

But, various tests on a small cluster with SSD disks showed that the solution with ephemerals was really the most interesting for what I want to do.

Problem: I don't believe you can have the system on the BOSS and the ephemerals on the NVMe disks.

So my questions are:

1) am I wrong and ephemerals are possible on NVMe (I use kolla-ansible to deploy, I haven't seen how to do that)?

2) or the solution is to create a Ceph cluster on the NVME of the 6 servers

3) or a better solution exists 

Thank you in advance if you can help me make these choices.