I saw multiple posts here on Isolation and role Heartbeat datastore "could" plays. I also read Deep Dive 6.7. Based on my understanding, would be the right way to defend the decision?
Decision:
vSAN heartbeat datastore will be disabled in the vSAN Stretch cluster?
Justification:
vSAN has a single datastore. When ESXi host is isolated it will try to confirm by trying to reach vSAN network default gateway in the respective site. If vSAN GW ist not reachable, ESXi host is declared as isolated.
Design Implication:
There could be a corner case when ESXi host is unable to declare itself isolated but at the same time will lose locks on the vSAN datastore, vSphere HA will trigger vSphere HA response and potential two VM with same MAC, IP might be running in the environment.
Additional Settings:
1. Isolation Response set to power off
2. vSAN subnet's Isolation address configured in the Availability zones
3. Disabled default Isolation address
All HA considerations are indeed described in the vSAN book and on storagehub here: Cluster Settings – vSphere HA | vSAN Stretched Cluster Guide | VMware
Datastore Heartbeats are not used when you only have vSAN. So in your situation it doesn't matter at all, you don't have any other datastores for a heartbeat to storage. I am not sure what you mean with the design implication to be honest.
All HA considerations are indeed described in the vSAN book and on storagehub here: Cluster Settings – vSphere HA | vSAN Stretched Cluster Guide | VMware
Datastore Heartbeats are not used when you only have vSAN. So in your situation it doesn't matter at all, you don't have any other datastores for a heartbeat to storage. I am not sure what you mean with the design implication to be honest.
Might be most stupid thing I might have done. I should delete this thread.
When I see again (in foresight), "Decision Implication" is completely wrong Label.
I skipped "Folder Structure with vSAN for HA" from the "Handbook" and directly jumped to "Heartbeat Datastores, When Can They Help?"
And "Heartbeat Datastores, When Can They Help?" has confused me to think that it is supported. I think this section when you have both vSAN and Traditional storage.