Identifying issues with and setting up name resolution on ESX/ESXi Server
Unable to configure VMware High Availability (HA).
Configuring VMware HA fails at about 97% completion.
Configuring VMware HA fails between 85 to 91%.
Reconfiguring VMware HA fails.
Adding an ESX host to a cluster fails.
Enabling VMware HA in a cluster fails.
These errors are generated when attempting to configure VMware HA:
An error occurred during configuration of the HA agent on the host
HA agent on <ESX> in cluster <cluster> in <Datacenter> has an error
Error: Cannot complete the configuration of the HA agent on the host. Other HA configuration error
cmd addnode failed for primary node:/opt/vmware/aam/bin/ft_startup failed
Host fails to remediate or exit Maintenance Mode.
You see the error:
Operation timed out
In the Tasks view of VirtualCenter/vCenter Server, you see the error:
There are errors during the remediation operation Failed to find host
Update Manager is unable to scan ESX/ESXi hosts.
The errors listed in the Symptoms section are generated as a result of name resolution issues.
This article guides you through identifying issues with name resolution which can seriously impact the normal operation of ESX/ESXi, particularly in HA clustered environments. The article also details correctly configuring host files when there is no DNS server in the environment, or if the DNS server is incorrectly configured.
There is a problem with name resolution if any of these tests fail. ESX/ESXi hosts must be able to find each other by:
Fully Qualified Domain Name (FQDN)
If an issue with name resolution has been identified it must be resolved either on the DNS server or by using hosts files.
Note: After making any changes to DNS or hosts files, ensure that you delete the file /etc/FT_HOSTS (or/etc/opt/vmware/aam/FT_HOSTS and /var/run/vmware/aam/FT_HOSTS) on all affected ESX/ESXi hosts.
The hosts file on the ESX host is located at /etc/hosts.
Open the file for editing using a text editor such as nano or vi.
Example hosts file:
# Do not remove the following line, or various programs # that require network functionality will fail. 127.0.0.1 localhost.localdomain localhost
# Any line beginning with a pound sign is a comment and will not be read. 192.168.0.5 esx-server-1.domain.com esx-server-1 192.168.0.6 esx-server-2.domain.com esx-server-2
# The VMware Virtual Center Server must also have an entry here 192.168.0.20 virtualcenter.domain.com virtualcenter
localhost must always be present in the hosts file. Do not modify or remove the entry for localhost.
The hosts file must be identical on all ESX/ESXi hosts in the cluster.
There must be an entry for every ESX/ESXi host in the cluster.
Every host must have an IP address, Fully Qualified Domain Name (FQDN), and short name.
The hosts file is case sensitive. Be sure to use lowercase throughout the environment.
Note: This issue has been resolved in vCenter 2.5 U3 and above. For more information, see VMware HA Can Be Configured on a Cluster Regardless of the Letter Case of the ESX Server Host Names in the Resolved Issues section of the VirtualCenter 2.5 Update 3 Release Notes.