Thanks, but as I mentioned, the VMFS is not corrupt, and has live VMs running on it. So I cannot switch them to RDMs to mount within a VM without powering down the VMs (not really an option) or moving the VMs to another disk (risks that I'd clobber whichever VMFS had the original VM.)
I have the ESXi host booted from Ubuntu, but I may have a new limitation ... not sure yet if this distro has any drivers to support the FC cards installed on the server. And we have to open access on our firewall to enable the host (would be the same limitation for a VM) to download the software.
I'll keep you posted, but this is looking less possible to achieve in our case.