6.5.1

Table Of Contents
Cause
To restart a Secondary VM, vSphere HA requires that the Primary VM be running on a host that is in the
same partition as the one containing the vSphere HA master host responsible for the FT pair. In addition,
the vSphere HA agent on the Primary VM’s host must be operating correctly. If these conditions are met,
FT also requires that there be at least one other host in the same partition that is compatible with the FT
pair and that has a functioning vSphere HA agent.
Solution
To fix this condition, check the vSphere HA host states reported by vCenter Server. If hosts are identified
as partitioned, isolated, or unreachable, resolve the problem before proceeding. In some situations, you
can resolve a restart problem by reconfiguring vSphere HA on the host that vCenter Server is reporting as
the master host. However, in most situations, this step is insufficient, and you must resolve all host state
problems.
After you have addressed any host state problems, check if there are any hosts in the cluster other than
the Primary VM's that are compatible with the FT virtual machine pair. You can determine compatibility by
trying to migrate the Primary VM to other hosts. Address any incompatibilities that are discovered.
Role Switch Behavior Problems
vCenter Server can report that the Primary VM of a vSphere Fault Tolerance virtual machine pair is
powered off, but the Secondary VM is powered on.
Problem
After a failover occurs, vCenter Server might incorrectly report that the Primary VM is powered off and
registered to its original host, and that the Secondary VM is powered on and registered to its original host.
Cause
This error occurs when vCenter Server is unable to communicate with the hosts on which the Primary VM
and Secondary VM are actually running. vCenter Server reports these hosts as not responding and the
problem persists until vCenter Server is able to communicate with the hosts.
Solution
To fix this problem, resolve the networking problem that is preventing vCenter Server from communicating
with the hosts in the cluster.
Troubleshooting VM Component Protection
If you enable VM Component Protection (VMCP) for your vSphere HA cluster, it provides protection
against datastore accessibility failures that can affect a virtual machine running on one of the cluster's
hosts.
If the response that you have configured VMCP to make for such a failure is not run, you should
troubleshoot to determine the cause.
vSphere Troubleshooting
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