From what I read about VMFS yes ceph allows you to have a shared block devices (RBD = rados block devices) across a cluster, and proxmox VE HA makes sure only o

From what I read about VMFS yes ceph allows you to have a shared block devices (RBD = rados block devices) across a cluster, and proxmox VE HA makes sure only one instance of the VM is active on the cluster to avoid having multiple writers to the same disk image.