Knowledge Base

This article guides you through the process of troubleshooting a VMware HA cluster. The article identifies common configuration problems as well as confirming the availability of required resources on your ESX Server.

Note: For troubleshooting steps specific to VMware vCenter Server 5.0.x HA/FDM, please see the below KB.

• For VMware vCenter Server 5.0 HA/FDM troubleshooting, see Troubleshooting Fault Domain Manager (FDM) issues (2004429).
• For the Japanese version of this article, see VMware HA (High Availability) のトラブルシューティング (2001526)

Validate that each troubleshooting step below is true for your environment. Each step provides instructions or a link to a document, in order to eliminate possible causes and take corrective action as necessary. The steps are ordered in the most appropriate sequence to isolate the issue and identify the proper resolution. Please do not skip a step.

Most issues can also be solved by disabling HA and then re-enabling it. Be sure to do this before proceeding with these steps.

Note: If you perform a corrective action in any of these steps, attempt to re-enable VMware HA again.

1. Check the release notes for current releases to see if the problem has been resolved in a bug fix. See the Documentation page for vSphere 4 or VMware Infrastructure 3.
   
   
2. Verify that there are enough licenses to configure VMware HA. For more information, see Verifying that a feature is licensed (1003692).
   
   
3. Verify that name resolution is correctly configured on the ESX Server. For more information, see Identifying issues with and setting up name resolution on ESX/ESXi Server (1003735).
   
   
4. Verify that name resolution is correctly configured on the vCenter Server. For more information, see Configuring name resolution for VMware vCenter Server (1003713).
   
   
5. Verify that the time is correct on all ESX Servers with the date command. For more information on setting up time synchronization with ESX Server, see Installing and Configuring NTP on an ESX host (1339).
   
   
6. Verify that network connectivity exists from the VirtualCenter Server to the ESX Server. For more information, see Testing network connectivity with the ping command (1003486).
   
   
7. Verify that network connectivity exists from the ESX Server to the isolation response address. For more information, see Testing network connectivity with the ping command (1003486).
   
   
8. Verify that all of the required network ports are open. For more information, see Testing port connectivity with Telnet (1003487).
   
   Notes:
   
   
   • HA uses these ports:
     
     Incoming port: TCP/UDP 8042-8045
     Outgoing port: TCP/UDP 2050-2250
     
     
   • Ensure that AAM (Automated Availability Manager) is enabled on the ESX Security Profile. If these ports are not open on the ESX firewall, HA cannot configure.
     
     
     
9. If configured with Advanced Settings, confirm that the configuration is valid. For more information, see Advanced Configuration options for VMware High Availability (1006421).
   
   
10. Verify that the correct version of the VirtualCenter agent service is installed. For more information on determining agent versions and how to manually uninstall and reinstall the HA agents on an ESX host, see Verifying and reinstalling the correct version of the vCenter Server agents (1003714).
    
    
11. Verify the VirtualCenter Server Service has been restarted. To restart the VirtualCenter Server Service, see Stopping, starting, or restarting vCenter services (1003895).
    
    
12. Verify that VMware HA is only attempting to configure on one Service Console. For more information, see VMware High Availability configuration issues when an iSCSI Service Console is on the same network (1003789) .
    
    
13. Verify that the VMware HA cluster is not corrupted. To do this you need to create another cluster as a test. For more information, see Recreating a VMware High Availability Cluster in vSphere (1003715).
    
    
14. Verify that that UDP 8043 packets used for the HA backbone communications are not dropped between the ESX hosts. For more information see HA fails to configure at 90% completion with the error: Internal AAM Error - agent could not start (1018217).
    
    
15. Ensure that the ESXi host userworld swap option is enabled. For more information see ESXi hosts without swap enabled cannot be added to a VMware High Availability Cluster (1004177).

Notes:

If your problem still exists after trying the steps in this article:

• Gather the VMware Support Script Data. For more information, see Collecting diagnostic information for VMware products (1008524).
• File a support request with VMware Support and note this KB Article ID in the problem description. For more information, see How to Submit a Support Request.

Additional Information

Verify the contents of the /etc/hosts files on the ESX/ESXi host and ensure the IP address of the host in the DNS is the same as the IP address in the hosts configuration file. Also ensure that the IP, FQDN, and shortname are added to the ESX/ESXi hosts file. For more information, see:

• Troubleshooting the VMware High Availability error: Unable to contact the primary host in a cluster (1004633)
• VMware HA fails with the error: AAM Agent did not start (1004965)