6.4

Reference Guide
32 VMware, Inc.
Recovering From a Failover
A failover differs from a switchover. A switchover is a controlled switch (initiated manually from the vCenter
Server Heartbeat Console, or initiated by vCenter Server Heartbeat when preconfigured) between the active
and passive servers. A failover happens when any of the following fail on the active server: power, hardware,
or VMware Channel communications. The passive server waits a preconfigured time after the first missed
heartbeat before initiating a failover. When this period expires, the passive server automatically assumes the
active role and starts the protected applications.
The following recovery scenario is based on vCenter Server Heartbeat configuration with the Primary server
as active and the Secondary server as passive.
A failover has occurred and the Secondary server is now running as the active server.
1 Review event logs on both servers to determine the cause of the failover. For assistance, use the Log
Collector tool to collect information and send the output to VMware Support.
2 If any of the following issues exist on the Primary server, performing a switchback to the Primary server
may not be possible until other important actions are carried out. Do not restart vCenter Server Heartbeat
until the following issues have been resolved:
 Hard Disk Failure – Replace the defective hard disk.
 Power Failure – Restore power to the Primary server.
 Virus – Clean the server of all viruses.
 Communications – Replace or repair the physical network hardware.
 Blue Screen – Determine cause and resolve. As required, submit the dump file to VMware Support
(www.vmware.com/support) for analysis.
3 Run the Configure Server wizard and verify the server identity is set to Primary and the Active Server is
set to Secondary. Click Finish to accept the changes.
4 Disconnect the VMware Channel network cables or disable the network card.
5 Resolve the list of possible failures.
6 Restart this server and reconnect or enable the network card again.
7 After restart, check that the Taskbar icon now reflects the changes by showing P / – (Primary and passive).
8 On the Secondary active server or from a remote client, launch vCenter Server Heartbeat Console and
confirm that the Secondary server is reporting as active.
If the Secondary server is not displaying as active, perform the following steps:
1 If the vCenter Server Heartbeat Console is unable to connect remotely, try running it locally. If you are still
unable to connect locally, use the Service Control Manager to verify that the service is running. If the
service is not running, review the event logs for a cause.
2 Run the Configure Server wizard and confirm that the server identity is set to Secondary and the Active
Server is set to Secondary.
3 Verify that the protected application is accessible from clients. If accessible, start vCenter Server Heartbeat
on the Secondary server. If the application is not accessible, review the application logs to determine why
the application is not running.
N
OTE When failover conditions, such as a power failure, cause failures in both active and passive servers, a
condition may result that causes both servers to restart in passive mode. In this situation, manual intervention
is required. See Appendix 10, “Two Passive Servers,” on page 73.
N
OTE If vCenter Server Heartbeat is running, you can run the Configure Server wizard but any changes
made will not be saved.