Knowledge Base

The first indication that VMware vCenter Server Heartbeat may be experiencing two passive servers is when users are unable to connect to protected applications. This situation must be addressed immediately. If alerts are configured, you receive notification that replication is not functioning properly.

Possible causes of this behavior are:

• The result of sudden failure on the active server – for example, unexpected termination of the Neverfail Server R2 service, a transient power failure, a server reset triggered from the Power or Reset button, or any other type of unclean shutdown. Following an unclean shutdown, an active server automatically assumes the passive role to isolate itself from the network until the failure can be investigated.
• The active server suffers a failure before completion of the handshake which establishes the VMware Channel. In this situation, the passive server has no way of detecting that the active server is not responding when the failure occurs. No channel connection was established, so it is impossible for the passive server to determine the condition of the active server. The active server may suffer a transient failure as described above and the passive server cannot respond by failing over into the active role. This leaves both servers in the passive role.
• Both Primary and Secondary server experience a power outage simultaneously. In this situation, a failover is not be possible. When the servers are rebooted, each displays the error:
  
  Cannot start replication because previous run did not shutdown properly. Check configuration.
  
  Note: If you attempt to start vCenter Server Heartbeat without reconfiguring one server in the pair as active, vCenter Server Heartbeat responds with the warning:
  
  [U16] Serious configuration mismatch between the two servers. Please reconfigure so there is one and only one Primary, and one and only one Active.

To resolve the issue:

1. Determine which server must be active.
2. If vCenter Server Heartbeat is running on either server, shut it down. Leave any protected applications running on the server you have chosen to make active.
3. On the server you want to make active:
   
   
   1. Open the Configure Server wizard.
   2. Click the Machine tab.
   3. Select the active role,
   4. Click Finished. Do not change the Identity (Primary / Secondary).
   5. Save the changes and exit the wizard.
      
      
4. On the server you want to make passive, open the Configure Server wizard and confirm that the role is passive. Do not change the Identity (Primary / Secondary). Exit the wizard.
5. Reboot both servers. This ensures that all protected application services are stopped on the passive server and started on the active server.
6. Start vCenter Server Heartbeat on both servers.