Cannot configure VMware HA when the ESX/ESXi hostname has more than 26 characters

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Cannot configure VMware High Availability (HA) if the ESX/ESXi hostname has more than 26 characters
• Configuring VMware HA fails when the hostname has more than 26 characters
• You see the error:
  
  Unable to contact a primary HA agent
  
  
• Adding the host to vCenter Server succeeds, but VMware HA fails to configure
• You see the following error in the /var/log/vmware/aam/addnode.log:
  
  Trying to talk to self ('<hostname>'), yet there is no sites file.
  [find_active_primary ] Could not connect to any node to find an active primary .
  [active_primary_ftcli] could not find an active primary on which to execute the command.
  
  

configuring-ha-fails

Environment

VMware ESX 4.0.x
VMware ESXi 4.1.x Embedded
VMware ESXi 3.5.x Embedded
VMware ESXi 4.0.x Installable
VMware ESXi 4.0.x Embedded
VMware ESX 4.1.x
VMware ESXi 3.5.x Installable
VMware ESXi 4.1.x Installable
VMware ESX Server 3.5.x

Resolution

Though vCenter Server allows ESX/ESXi short hostnames to have up to 31 characters, the VMware HA component VMAP adds 5 characters to the hostname during the HA configuration. Therefore, when the hostname has more than 26 characters, VMware HA configuration fails.

To resolve this issue, if you plan to configure HA on the host, ensure that the ESX/ESXi short hostname has 26 or lesser characters.

Note: This does not impact the maximum character limit of 255 on the full name of ESX/ESXi hosts. This also does not apply to FDM 5 clusters.