Configuration:
Netapp (SAN) providing a 5GB FC LUN to VMware hosts (datastore).
(2) Server 2012R2 datacenter VMs configured with a 5GB shared vmdk using paravirtual SCSI controller with SCSI Bus sharing set to "Physical" for hosting data.
Problem:
Whenever I put a file on the shared disk on VM1, the data does not show up on VM2. I have to reboot VM2 in order for the data to show up.
I am requiring this configuration for a failover cluster for my subordinate Certificate Authority servers thus the requirement to have data show up immediately.
Alibi:
Please request for additional information that may help your understanding or to help provide a thorough solution.
It sounds like you want to cluster your filesystem between two hosts. You seem to be looking for a Cluster Shared Volume, but that is typically supported for newer SQL clusters or Hyper-V. I don't know if it would be supported for Certificate Authorities.
Typically, a CA is configured on both hosts to be identical. They share a disk in an Active/Passive state so one host has full control of the disk while the other is showing it offline. If the witness host loses connectivity to the active host, it will activate the passive host and the filesystem will be available to the secondary host.
If you're looking for an Active/Active approach, you might be able to do it with MFCS using Cluster Shared Volumes, but I know MS doesn't support the configuration so I would not recommend it for production.