6.0.1

In most implementations, NIC teaming provides sufficient heartbeat redundancy, but as an alternative you
can create a second management network connection attached to a separate virtual switch. Redundant
management networking allows the reliable detection of failures and prevents isolation or partition
conditions from occurring, because heartbeats can be sent over multiple networks. The original
management network connection is used for network and management purposes. When the second
management network connection is created, vSphere HA sends heartbeats over both management network
connections. If one path fails, vSphere HA still sends and receives heartbeats over the other path.
NOTE Configure the fewest possible number of hardware segments between the servers in a cluster. The
goal being to limit single points of failure. Additionally, routes with too many hops can cause networking
packet delays for heartbeats, and increase the possible points of failure.
Using IPv6 Network Configurations
Only one IPv6 address should be assigned to a given network interface used by your vSphere HA cluster.
Assigning multiple IP addresses increases the number of heartbeat messages sent by the cluster's master
host with no corresponding benefit.
Best Practices for Interoperability
Observe the following best practices for allowing proper interoperability between vSphere HA and other
features.
vSphere HA and Storage vMotion Interoperability in a Mixed Cluster
In clusters where ESXi 5.x hosts and ESX/ESXi 4.1 or prior hosts are present and where Storage vMotion is
used extensively or Storage DRS is enabled, do not deploy vSphere HA. vSphere HA might respond to a
host failure by restarting a virtual machine on a host with an ESXi version different from the one on which
the virtual machine was running before the failure. A problem can occur if, at the time of failure, the virtual
machine was involved in a Storage vMotion action on an ESXi 5.x host, and vSphere HA restarts the virtual
machine on a host with a version prior to ESXi 5.0. While the virtual machine might power on, any
subsequent attempts at snapshot operations could corrupt the vdisk state and leave the virtual machine
unusable.
Using Auto Deploy with vSphere HA
You can use vSphere HA and Auto Deploy together to improve the availability of your virtual machines.
Auto Deploy provisions hosts when they power up and you can also configure it to install the vSphere HA
agent on such hosts during the boot process. See the Auto Deploy documentation included in vSphere
Installation and Setup for details.
Upgrading Hosts in a Cluster Using Virtual SAN
If you are upgrading the ESXi hosts in your vSphere HA cluster to version 5.5 or higher, and you also plan
to use Virtual SAN, follow this process.
1 Upgrade all of the hosts.
2 Disable vSphere HA.
3 Enable Virtual SAN.
4 Re-enable vSphere HA.
vSphere Availability
42 VMware, Inc.