Referencing the Per Limitations of Virtual SAN section of VMware Docs: "Virtual SAN does not support RDM, VMFS, diagnostic partition, and other device access features."
I'm interpreting this limitation to mean vSAN does not support provisioning an RDM to an individual disk that is already participating in a vSAN cluster; this makes sense. That being considered, I have a VM that requires access to Local Storage adjacent to the devices that comprise the vSAN, "outside of" the Virtual SAN. These adjacent devices will be SAS-attached SSDs on the same modern LSI SAS HBA (Non-RAID, JBOD) that supports up to 24 drives; the proposed RDM devices will be the same or similar to the drives currently participating in the vSAN. Additionally, I've confirmed that the LSI controller can support this per VMware KB document warning that the SAS controller supports "...SCSI Inquiry Vital Data Product (VPD) page code 0x83, which is used to directly address and communicate with RDM devices."
The goal is to create RDMs to some new local SSDs and attach them to 1:1 to VMs (VMDKs running on the vSAN). The VMs would be pinned to the host and therefore the RDM. These will be "app protected" VMs replicating to a failover VM on another host in the cluster.
I cannot think of any reason why this would not be supported for this use case/scenario but wanted to gather input & opinions.
Many thanks in advance.
ESXi 6U3
vSAN 6.2U3
