JetStream DR Configuration Errors – DNS Issues

This article applies to all JSDR software versions.

Problem

Communication issues between JetStream DR components and the host environment may occur due to DNS resolution problems. Proper DNS configuration is crucial for seamless communication between the JetStream DR Host, CIM/Object Store, and MMS Server. Validate and update DNS and host settings to ensure system stability and prevent communication errors.

Symptoms

• The JetStream DR plugin is registered but not visible under vCenter.
• Log entries indicating DNS resolution failures.
• Error messages related to CIM connectivity.
• Failure to register the Subscription ID (caused by failure of the MSA being able to communicate with the MMS server.)
• Failure to communicate with the object store (resulting in failure of storage account configuration).
• Cluster configuration errors, such as:
  IO Filter package installation on cluster failed with error: IO Filter package url might not be accessible from vCenter Server. Please make sure that Management Server is reachable from vCenter Server by its FQDN.

Validation

• Validate if the MSA is able to resolve the host FQDN, MMS server FQDN and object store endpoint.
  • Test this using the nslookup command.
• Communication can also be validated using the command: curl -v https://<FQDN>:443
  • Replace <FQDN> with the correct target device FQDN or IP.
  • This command should be executed via the MSA/DRVA CLI.

Solution

1. Ensure all network and security settings allow for proper DNS resolution.
2. Verify DNS configuration of the MSA and DRVA.
   • Log in to the MSA and DRVA and validate their DNS entries by checking the file: /etc/resolv.conf.
   • If the file is missing or incorrect, manually update the DNS entries.
3. Restart the VME2 service on the MSA.
4. If no DNS is configured, select the Register with IP option when registering the vCenter plugin or while using the RUN command to install JetStream DR for AVS.
5. To manually configure host-to-host resolution, the file /etc/hosts can be edited on the MSA and DRVA.
   • Add the following entries for the host, object store, and MMS server:
     • <object_store_ip> objectstore FQDN
     • <mms_server_ip> mms.azurewebsites.net
     • <host_server_ip> host FQDN

This step should be considered a temporary workaround. It is strongly recommended to directly address all underlying DNS issues as a permanent solution.

The DRVA is a stateless appliance, and manual changes to /etc/hosts will be lost after a reboot. Due to the stateless nature of the DRVA, persistent configurations should be handled through proper DNS setup.

Contact JetStream Support to confirm the IP of the MMS server.