Clean up duplicate DNS records of vCenter

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• Duplicate DNS records after configuring a vCenter Server High Availability environment might interrupt access to the vCenter Server system.

Environment

VMware vCenter Server 6.7.x

Cause

• After configuring or patching a vCenter Server High Availability environment followed by a failover, access to the vCenter Server system might be blocked due to duplicate DNS records for the vCenter Sever Appliance.

Resolution

The issue is resolved in 6.7U3b release of the product. Please ensure before patching vCenter Server High Availability environments, clean up duplicate DNS records from the DNS Server

Workaround:
To workaround the issue, follow the below steps:

Note: This is applicable to versions 6.7U3 and 6.7U3a. 

1. Remove the DDNS cron file using following command

rm -rf /etc/cron.d/dns_update.cron

2. Kill the DDNS daemon process using the process ID. The PID can be retrieved using following command.
   • root@test-ddns [ ~ ]# ps -eaf | grep ddns
      root 10632 1 0 08:31 ? 00:00:00 /usr/bin/python
       /usr/lib/applmgmt/ddns/py/ddns.py
   • kill -9 <PID_DDNS>
3. Remove the DDNS daemon entry from the prestart-applmgmt.sh file.
   • root@test-ddns [ ~ ]# vi /usr/lib/applmgmt/support/scripts/prestart-applmgmt
   • Remove following line from the script
     102 if isFeatureEnabled DDNS_Updater ; then
     103 /usr/bin/python /usr/lib/applmgmt/ddns/py/ddns.py
      104 fi
4. Restart the applmgmt

Service-control –restart applmgmt