I wrote this article about split brain scenarios for the vSphere Blog. Based on this article I received some questions around which “isolation response” to use. This is not something that can be answered by a simple “recommended practice” and applied to all scenarios out there. Note that below has got everything to do with your infrastructure. Are you using IP-Based storage? Do you have a converged network? All of these impact the decision around the isolation response.
The following table however could be used to make a decision:
| Likelihood that host will retain access to VM datastores | Likelihood that host will retain access to VM network | Recommended Isolation policy | Explanation |
| Likely | Likely | Leave Powered On | VM is running fine so why power it off? |
| Likely | Unlikely | Either Leave Powered On or Shutdown | Choose shutdown to allow HA to restart VMs on hosts that are not isolated and hence are likely to have access to storage |
| Unlikely | Likely | Power Off | Use Power Off to avoid having two instances of the same VM on the VM network |
| Unlikely | Unlikely | Leave Powered On or Power Off | Leave Powered on if the VM can recover from the network/datastore outage if it is not restarted because of the isolation, and Power Off if it likely can’t. |
“Which isolation response should I use?” originally appeared on Yellow-Bricks.com. Follow us on Twitter and Facebook.
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