After configuring a vSphere cluster for High Availability you might see this message on the summary page of your hosts. It’s a nice reminder that your VMkernel Port carrying management traffic only has one NIC available, and is flagged by the HA health check routine, run during HA configuration.
Go in an add a second NIC to the vSwitch containing your management VMkernel port and voila problem solved. (note this is my demo environment on my laptop – keep iSCSI traffic separated in production!)
However the error message won’t automatically go away – it can only be cleared by the health check script. To manually kick the script off right-click the host and choose “Reconfigure for vSphere HA”
You can monitor the progress in the Recent Tasks pane
When the reconfig completes the message will be cleared.
This also can happend like in my situation. 2 ESX nodes running with 2 x Quad Gigabit NICs.
We have separated traffic for 2-nodes-only VM running without access to LAN by just cross-over cable between 2 ESX servers (single cable). So 7 NICs remaining for usual traffic.
But this caused error like this..