With the falling price of network cards, there was a desire to build a two-node cluster with two points of failure, with an NVME disk on each node for shared storage. This was supposed to be a cluster option for home or a small business. The choice fell on drbd storage with rdma.
it seems there is no mention about the pve clustering - just setting up the drbd mirroring. so i have difficulties in understanding how this can work, as we need three nodes minimum with proxmox pve.
You use any 2 nodes (pve internal or external) for redundant storage representation and use all (or all others) pve nodes just as clients for vm/lxc images.