6.5.1

Table Of Contents
Troubleshooting Availability 5
The availability troubleshooting topics provide solutions to potential problems that you might encounter
when using your hosts and datastores in vSphere HA clusters.
You might get an error message when you try to use vSphere HA or vSphere FT. For information about
these error messages, see the VMware knowledge base article at http://kb.vmware.com/kb/1033634.
This chapter includes the following topics:
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Troubleshooting vSphere HA Admission Control
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Troubleshooting Heartbeat Datastores
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Troubleshooting vSphere HA Failure Response
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Troubleshooting vSphere Fault Tolerance in Network Partitions
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Troubleshooting VM Component Protection
Troubleshooting vSphere HA Admission Control
vCenter Server uses admission control to ensure that sufficient resources in a vSphere HA cluster are
reserved for virtual machine recovery in the event of host failure.
If vSphere HA admission control does not function properly, there is no assurance that all virtual
machines in the cluster can be restarted after a host failure.
Red Cluster Due to Insucient Failover Resources
When you use the Host Failures Cluster Tolerates admission control policy, vSphere HA clusters might
become invalid (red) due to insufficient failover resources.
Problem
If you select the Host Failures Cluster Tolerates admission control policy and certain problems arise, the
cluster turns red.
Cause
This problem can arise when hosts in the cluster are disconnected, in maintenance mode, not
responding, or have a vSphere HA error. Disconnected and maintenance mode hosts are typically caused
by user action. Unresponsive or error-possessing hosts usually result from a more serious problem, for
example, hosts or agents have failed or a networking problem exists.
VMware, Inc.
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