Topology Installation Fails with "Playbook failed to find /etc/DA.cfg on DA instance"

Products

• Network Observability

Issue/Introduction

During the DX NetOps Topology installation or upgrade, the Ansible playbook fails at the "Check DA Config Dir exists" task. The installer logs show the following error:

TASK [Check DA Config Dir exists] **********************************************
[ERROR]: Task failed: Action failed: Playbook failed to find /etc/DA.cfg on DA instance, Please check and ensure DA service running on the DA host
Origin: /opt/topology-installer-25.4.2/provisioning/roles/common/tasks/fetch_da_details.yaml:10:7

fatal: [DA]: FAILED! => {
    "assertion": "da_config_registry_stat.stat.exists",
    "changed": false,
    "evaluated_to": false,
    "msg": "Playbook failed to find /etc/DA.cfg on DA instance, Please check and ensure DA service running on the DA host"
}

Environment

 

• Product: DX NetOps Performance Management , NetOps Topology

• Version: 25.4.x

• Deployment: Distributed (Kafka, Neo4j, and Topology services on separate VMs)

 

Cause

The Topology installer uses an inventory file to identify the remote hosts for the various components. This error occurs if the IP address or hostname provided for the Data Aggregator (DA) is incorrect.

The installer attempts to connect to the provided IP to verify the existence of /etc/DA.cfg (a critical configuration file created during DA installation). If it connects to the wrong host, the file is not found, and the assertion fails.

Resolution

 

• Validate Inventory: Open the installation inventory file (typically inventory.ini or similar) and verify that the IP address/hostname assigned to the Data Aggregator entry is correct and reachable.

• Clean Up: Run the uninstallation script for the failed Topology components to ensure a clean state.

• Relaunch Installation: Correct the IP address in the inventory file and re-run the Topology installation script.

• Verify DA File: Manually log into the Data Aggregator host and confirm that /etc/DA.cfg exists and is readable:

  • ls -l /etc/DA.cfg

 

Additional Information

 

• The /etc/DA.cfg file contains environment variables such as da.data.home which are required for the Topology service to integrate with the Data Aggregator.