Cold migrating a virtual machine fails with the error: Failed to connect to host

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Unable to cold migrate a virtual machine
• Cold migrating a virtual machine fails
• You see the error:
  
  Failed to connect to host

• In the vpxa.log file located at /var/log/vpx/vmware/, you see the error:
  
  [2008-06-11 06:03:41.704 'App' 49224624 warning] Failed to bind heartbeat socket. Using any IP.

Environment

VMware ESX Server 3.0.x
VMware ESX Server 3.5.x
VMware VirtualCenter 2.5.x

Resolution

To resolve this error:

1. Run this command on the ESX host to ensure that the correct short name is used:
   
   hostname -s
   
   
2. Verify the hostname in /etc/hosts.
3. Remove the host from the VirtualCenter inventory.
4. Run these commands to manually remove vpxa rpm from the host:
   
   rpm -qa | grep vpx
   rpm -e <output command from previous>
   
   </output>
5. Add the host back to the VirtualCenter inventory. vpxa is re-installed.
6. It may be necessary to restart VMware VirtualCenter Server service. To restart VMware VirtualCenter Server service, see Stopping, starting, or restarting the vCenter Server service (1003895).

Additional Information

This issue may also occur due to firewall port blocking. For more information, see TCP and UDP Ports for vCenter Server, ESX hosts, and other network components management access (1012382). Working with firewall rules in ESX 4.x