Assuming that you want to use SAN as shared storage, a very high level description would be:
- Connect all proposed hosts to storage using standard SAN vendor suggested means
- Configure Multipath if used using SAN vendor best practices
- Ensure that you see SAN disks identically across all hosts
- Research pros and cons of Volume Manager / File System selection for your use case:
-- Starting point is here
https://pve.proxmox.com/wiki/Storage
-- In most cases your only PVE supported option out of the ones listed in the table is LVM (not-thin).
-- By using LVM you will be utilizing most integrated option where disk management can be done via PVE GUI/CLI/API
-- The cons - no thin provisioning and no snapshot support.
-- Other options worth researching - any Clustered File systems your are comfortable with, ie OCF2 etc.
-- Installing, configuring and supporting this CFS will be completely up to you.
Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox