6.5

Configuring Split-brain Avoidance
Split-brain Avoidance ensures that only one server becomes active if the VMware Channel connection is lost,
but both servers remain connected to the Principal (Public) network. Split-brain Avoidance works by pinging
from the passive server to the active server across the Principal (Public) network. If the active server responds,
the passive server does not failover, even if the VMware Channel connection is lost. WAN installations require
dierent IP addresses on the Principal (Public) network for the local and remote servers.
Procedure
1 To enable Split-brain Avoidance, open the Server: Monitoring page in the vCenter Server Heartbeat Console.
2 Click Congure Failover.
3 Select Prevent failover if channel heartbeat is lost but Active server is still visible to other servers (recommended).
Common Administrative Tasks in vCenter Server Heartbeat
The Server: Summary page provides the following buttons that allow you to quickly perform common
administrative tasks:
■
Make Active — Prompts to verify that you want to make the passive server in the pair active. Click Yes.
■
Shutdown — Prompts you to select the server(s) to shut down. If you select the active server, additional
options to stop or not stop protected applications appear in the dialog. Click OK.
■
Start Replication — Opens the Start Replication Options dialog. Select to start or not start the protected
applications and click OK. By default, all protection modes start when vCenter Server Heartbeat starts
and a manual start is not required unless the system stopped in response to an automated stop.
■
Stop Replication — Opens the Stop Replication Options dialog. Use this method to stop replication, such
as to contain a malware infection or to upgrade a protected application. Select whether to stop or not stop
protected applications and click OK. Replication of data les stops and, if selected, protected applications
also stop.
Note The vCenter Server Heartbeat service continues to run on the servers, providing heartbeats and protecting
the system and network facets of the active server.
■
Start Applications — Click to start the protected applications on the active server.
■
Stop Applications — Click to stop the protected applications on the active server.
■
Congure — Click to open the Congure dialog. Select the radio button corresponding to whether you
want to stop or leave the protected applications running when vCenter Server Heartbeat is shut down.
You can select whether to leave protected applications running upon shutdown when a net stop command
is issued, and to start protected applications upon startup when a net start command is issued. Type a
number (seconds) or use the arrow buttons to select an alert threshold value for time dierence between
servers, which is checked at handshake following startup. Click OK.
Forcing a Switchover
After conguring vCenter Server Heartbeat to protect all the required applications and data, the Secondary
server can take over from the Primary server in a managed and seamless manner called a managed switchover.
This is particularly useful when maintenance work performed on the Primary server requires rebooting the
server.
VMware, Inc. 35
Chapter 3 Server Protection