Data Domain : Resolving GUI Issues with Hostname

Summary: DD System Manager does not work with DD hostname in Data Domain GUI. The issue occurs when trying to access the GUI using the hostname, resulting in a 400 error, whereas accessing with the IP address does not cause any issues. The problem is related to the hostname format, specifically the use of an underscore character, which is not allowed in domain names. The issue was resolved by updating the hostname to a valid format, regenerating the certificates, and updating the DNS entries. The customer was able to load the GUI successfully after these changes. ...

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Symptoms

The customer is experiencing an issue with the Data Domain GUI not working with the hostname.

  • When connecting to the GUI with the hostname, the customer receives a 400 error, which is a client-side error.
  • However, when accessing the GUI with the IP address, there is no issue.
  • Accessing the CLI through Putty with the hostname and IP address both work fine.

Cause

The root cause of the issue is related to the hostname format used by the customer.

  • The hostname contains an underscore (_) character, which is not a valid character in a domain name.
  • This causes an error in the Apache Tomcat logs, specifically the "The character [_] is never valid in a domain name" error message.
  • The error occurs when the customer tries to access the GUI using the hostname, resulting in a 400 error.
  • The hostname can only be 63 characters long

Caution: Using an underscore in the hostname can cause issues with the GUI and may require regeneration of certificates.

Relevant error messages and codes:

  • Apache Tomcat log error: "The character [_] is never valid in a domain name."
  • HTTP error code: 400 (Bad Request)

Resolution

To resolve this issue, follow the steps below:

  1. Update the hostname: Update the hostname of the Data Domain to a valid hostname without underscores. This can be done from the GUI (using the IP address) by following the steps mentioned in the Administration Guide.
  2. Regenerate the certificates: After updating the hostname, regenerate the certificates. This will ensure that the HTTPS certificate is updated with the new hostname.
  3. Update DNS entries: Update the DNS entries to reflect the new hostname. This will ensure that the replication peer system can continue to resolve the new hostname.
  4. Modify replication: Modify the replication configuration to use the new hostname.
  5. Verify the issue: Verify that the issue has been resolved by accessing the GUI with the new hostname. If the issue persists, contact Dell Support for further assistance.
  6. All above steps are documented in this  kb: https://www.dell.com/support/kbdoc/en-us/000056665/89823-changing-data-domain-hostname

Caution: If you are not comfortable with modifying the replication configuration, it is recommended to contact Dell Support for assistance.
Note: It is essential to update the DNS entries and regenerate the certificates to ensure that the replication peer system can continue to resolve the new hostname.

Affected Products

Data Domain
Article Properties
Article Number: 000229461
Article Type: Solution
Last Modified: 19 Dec 2024
Version:  2
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