Ceph RBD can technically support multi-writer access through exclusive locking, but it won't be the same as multi-writer. You can set up a radosgw outside of t

Ceph RBD can technically support multi-writer access through exclusive locking, but it won't be the same as multi-writer. You can set up a radosgw outside of the proxmox and use objects. But ceph is fundamentally a distributed object store, shared LUNs with block level multi-writer is fundamentally a tightly coupled solution. If you have a legacy need that has OCFS or a quorum drive, the underlying tools proxmox is an abstraction can sometimes be used as these types of systems tend to be pets. But if you were just using multi-writer because it was there, there are alternatives that are typically more robust under the shared nothing model like Ceph uses. But it is all tradeoffs and horses for courses.