Alarm: Skyline Health has detected issues in your vSphere environment on Folder Datacenters

Products

• VMware vCenter Server

Issue/Introduction

• From time to time, you get the alarm  "Skyline Health has detected issues in your vSphere environment on Folder Datacenters"
• If you check SkylineHealth the status is normal
• In vCenter log files you may see lines similar to:
  • /var/log/vmware/analytics/analytics.log 

com.vmware.ph.client.api.exceptions.PhClientConnectionException: java.net.UnknownHostException: vcsa.vmware.com: No address associated with hostname

• • /var/log/vmware/dnsmasq.log

<timestamp>  dnsmasq: forwarded vcsa.vmware.com to <DNS_SERVER1_IP>
<timestamp>  dnsmasq: forwarded vcsa.vmware.com to <DNS_SERVER2_IP>
<timestamp>  dnsmasq: reply vcsa.vmware.com is NODATA-IPv4

 

Environment

vCenter Server 8.x

Cause

One or more of your DNS servers replies  NODATA-IPv4 for  vcsa.vmware.com 

NODATA means that the domain exists, but there's no information of the  specified type (in this case A records) associated with that domain.

Resolution

 

As it is a transient issue from your DNS server,

• Investigate your DNS server logs for  vcsa.vmware.com  resolution
• Apply the following workaround: insert vcsa.vmware.com address in vCenter /etc/hosts file
• • Steps to validate the communication between vCenter to vcsa.vmware.com

root@<vcenter_hostname>[ ~ ]# nslookup vcsa.vmware.com
Server:         127.0.0.1
Address:        127.0.0.1#53

Non-authoritative answer:

Name:    vcsa.vmware.com
Address: <vcsa.vmware.com_ipv6_1> 
Name:    vcsa.vmware.com
Address: <vcsa.vmware.com_ipv6_2> 
Name:    vcsa.vmware.com
Address: <vcsa.vmware.com_ipv4_1>   <<<< The IPv4 IPs listed will be used in workaround
Name:    vcsa.vmware.com
Address: <vcsa.vmware.com_ipv4_2> 

 

• • Before editing the /etc/hosts file in the vCenter server appliance. 

root@<vcenter_hostname> [ ~ ]# cat /etc/hosts
# Begin /etc/hosts (network card version)

# VAMI_EDIT_BEGIN
# Generated by Studio VAMI service. Do not modify manually.
127.0.0.1  <venter_fqdn> <vcenter_hostname> localhost
::1  <venter_fqdn> <vcenter_hostname> localhost ipv6-localhost ipv6-loopback
# VAMI_EDIT_END

• • After editing the /etc/hosts file in the vCenter server appliance. 

root@<vcenter_hostname>[ ~ ]# cat /etc/hosts

# Begin /etc/hosts (network card version)

# VAMI_EDIT_BEGIN
# Generated by Studio VAMI service. Do not modify manually.
127.0.0.1  <venter_fqdn> <vcenter_hostname> localhost
::1  <venter_fqdn> <vcenter_hostname> localhost ipv6-localhost ipv6-loopback
# VAMI_EDIT_END

<vcsa.vmware.com_ipv4_1>  vcsa.vmware.com                    <<<<<< Line added