6.5.1

Table Of Contents
Cause
A host is network isolated if both of the following conditions are met:
n
Isolation addresses have been configured and the host is unable to ping them.
n
The vSphere HA agent on the host is unable to access any of the agents running on the other cluster
hosts.
Note If your vSphere HA cluster has vSAN enabled, a host is determined to be isolated if it cannot
communicate with the other vSphere HA agents in the cluster and cannot reach the configured isolation
addresses. Although the vSphere HA agents use the vSAN network for inter-agent communication, the
default isolation address is still the gateway of the host. Hence, in the default configuration, both networks
must fail for a host be declared isolated.
Solution
Resolve the networking problem that is preventing the host from pinging its isolation addresses and
communicating with other hosts.
Configuration of vSphere HA on Hosts Times Out
The configuration of a vSphere HA cluster might time out on some of the hosts added to it.
Problem
When you enable vSphere HA on an existing cluster with a large number of hosts and virtual machines,
the setup of vSphere HA on some of the hosts might fail.
Cause
This failure is the result of a time out occurring before the installation of vSphere HA on the host(s)
completes.
Solution
Set the vCenter Server advanced option config.vpxd.das.electionWaitTimeSec to value=240. Once this
change is made, the time outs do not occur.
Troubleshooting vSphere Auto Deploy
The vSphere Auto Deploy troubleshooting topics offer solutions for situations when provisioning hosts
with vSphere Auto Deploy does not work as expected.
vSphere Auto Deploy TFTP Timeout Error at Boot Time
A TFTP Timeout error message appears when a host provisioned with vSphere Auto Deploy boots. The
text of the message depends on the BIOS.
vSphere Troubleshooting
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