6.6

vCenter Server Heartbeat Failover Processes
vCenter Server Heartbeat provides for failover from one node to the other node when initiated manually by the
administrator or automatically as a result of hardware, operating system, network communications, protected
applications, or services failure. Failover changes the role of the active and passive nodes depending on the
status of the active node.
vCenter Server Heartbeat failovers are categorized by how the failover is initiated.
■
When a failover is initiated manually by an administrator, the failover gracefully changes the roles between
the active node and the passive node.This type of failover is frequently used to perform maintenance on
the node or its software.
■
If a failover is initiated automatically due to hardware, operating system, or network communications
rendering the active node unavailable, vCenter Server Heartbeat considers the active node has failed and
immediately initiates the process to change the role of the passive node to active.
■
Should vCenter Server Heartbeat detect that the active node is alive but that a protected application or
service has failed, it can first attempt to restart the application or service to correct the problem and if
unsuccessful, initiate a failover causing the active and passive nodes to change roles making the passive
node active and the active node passive.
Failover - Manually Initiated by an Administrator
You can click Make Active on the Heartbeat tab of the vSphere Web Client or the Server: Summary page of
the vCenter Server Heartbeat Console to manually initiate a failover. When a failover is triggered, the running
of protected applications is gracefully transferred from the active node to the passive node in the pair. The
roles of the nodes are reversed.
Figure 1- 6. Failover
A manually initiated failover performs the following steps:
1 Stop the protected applications on the active node. After the protected applications stop, no more disk
updates are generated.
2 Send all updates that are still queued on the active node to the passive node. After this step, all updates
are available on the passive node.
14 VMware, Inc.
vCenter Server Heartbeat Administrator's Guide