We wanted to get the word out ASAP on another KB article today. This one
involves VMware High Availability (HA), and customers with this specific
configuration with vSphere 4 need to be aware of this bug.
In vSphere 4.0, HA does NOT failover VMs when an host failure occurs. When
the ESX host COS IP address in the cluster are configured with certain IP
address the node failure detection algorithm fails.
IP Range – HA Functionality
0.x.x.x – 2.x.x.x – Failover Works
3.x.x.x – 9.x.x.x – Failover DOES NOT
work
10.x.x.x – 25.x.x.x – Failover works
26.x.x.x – 99.x.x.x – Failover
DOES NOT work
100.x.x.x – 255.x.x.x – Failover works
The issue has been seen and reported on Class A IP Addresses. If your ESX
COS/Management IP Address is on an internal 10.x.x.x or 192.x.x or if you use an
Class B or Class C IP address, then you will not be affected by this issue.
Note that our team is working on a permanent solution to this issue.
Continue reading vSphere 4.0 HA cluster may not fail VMs over during host failure
when ESX Host IP is configured with certain Class A IP address.
