6.5.1

Table Of Contents
Problem
While the virtual machines running on the host continue to be monitored by the master hosts that are
responsible for them, vSphere HA's ability to restart the virtual machines after a failure is affected. First,
each master host has access to a subset of the hosts, so less failover capacity is available to each host.
Second, vSphere HA might be unable to restart a FT Secondary VM after a failure (see Primary VM
Remains in the Need Secondary State).
Cause
A host is reported as partitioned if both of the following conditions are met:
n
The vSphere HA master host to which vCenter Server is connected is unable to communicate with
the host by using the management (or VMware vSANā„¢)network, but is able to communicate with that
host by using the heartbeat datastores that have been selected for it.
n
The host is not isolated.
A network partition can occur for a number of reasons including incorrect VLAN tagging, the failure of a
physical NIC or switch, configuring a cluster with some hosts that use only IPv4 and others that use only
IPv6, or the management networks for some hosts were moved to a different virtual switch without first
putting the host into maintenance mode.
Solution
Resolve the networking problem that prevents the hosts from communicating by using the management
networks.
vSphere HA Agent is in the Network Isolated State
The vSphere HA agent on a host is in the Network Isolated state. User intervention is required to resolve
this situation.
Problem
When a host is in the Network Isolated state, there are two things to consider -- the isolated host and the
vSphere HA agent that holds the master role.
n
On the isolated host, the vSphere HA agent applies the configured isolation response to the running
VMs, determining if they should be shut down or powered off. It does this after checking whether a
master agent is able to take responsibility for each VM (by locking the VM's home datastore.) If not,
the agent defers applying the isolation response for the VM and rechecks the datastore state after a
short delay.
n
If the vSphere HA master agent can access one or more of the datastores, it monitors the VMs that
were running on the host when it became isolated and attempts to restart any that were powered off
or shut down.
vSphere Troubleshooting
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