Yes it is "allowed" but note the CPU requirements for 6.7 also:
'VMware provides a vSAN Witness Appliance for those customers who do not wish to use a physical host for this role'...'This can include an ESXi Free licensed host'
"a physical host running the free version of ESXi (selected during VSAN 2 node setup, and not added to the cluster beforehand) - but it does require VSAN licensing"
It doesn't require a vSAN license - only a vSphere license (whichever has the requirements you need as it can also run other VMs on it if required/capable) - vSAN licensing is always on the cluster-level, a standalone physical Witness doesn't need to be in a vSphere cluster.
Thanks for the reply - that does look to be correct.
In the VMware documentation regarding the Physical witness, it states the following: -
If using a physical host as a vSAN Witness Host, it must be licensed with a valid vSphere license. This does not require the same licensed edition as the vSAN Cluster it is supporting.
Does the free esxi license qualify as a valid license, assuming that this host won't be used for any other purpose...
"Does the free esxi license qualify as a valid license, assuming that this host won't be used for any other purpose..."
Yes, as per my first reply (and as noted in the referenced documentation).
Thanks - admittedly I didn't click the link on your first post and went straight to your second post, doh!
Thanks for your help, much appreciated