Symptoms

• Data Domain system does not respond to commands or network requests
• Backup operations fail or stall
• System appears to be offline, unavailable or hung

Applies to:

• All Data Domain Models
• All Software Releases

Possible Causes:

Unresponsiveness may result from one or more of the following:

• • Incorrect DNS configuration
  • Network connectivity failure or intermittent issues
  • Faulty or disconnected network/SAS cables
  • Duplicate IP addresses on the network
  • Excessive stream count exceeding performance limits
  • CPU saturation
  • Improper SAS topology (for systems with external shelves)
  • Power issues - such as, system powered off
  • Host restrictions by adminaccess
  • Misconfigured virtual network settings (for DDVE systems)

Solution:

Follow these steps in order to isolate and resolve the issue:

• Links my require customer login.

1. Verify DNS Configuration
   Ensure that DNS entries are correct. Misconfigured DNS can interrupt connectivity and make the system appear unresponsive.

   • Data Domain - Configuring the DDR with a DNS Server.

2. Check Network Connectivity
   Confirm that the system can communicate over the network. Use ping or traceroute tools to validate.

   • Data Domain - Verifying Network Connectivity is working properly. 

3. Inspect Network Cables
   Ensure that all cables are securely connected and functioning. Replace any suspect cables.

   • Ensuring the Data Domain system is Connected to the Network

4. Identify Duplicate IPs
   Scan the network for IP conflicts. Duplicate IPs can cause intermittent connectivity.

   • Data Domain - Identifying Duplicate IPs.

5. Review Stream Count
   Check if the system is handling more streams than recommended. Reduce stream count if necessary.

   •  Data Domain - Performance Tuning: Managing Data Streams.

6. Monitor CPU Utilization
   Use system tools to verify CPU load. High utilization can delay or block system responses.

   • Data Domain - Reviewing CPU Utilization.

7. Validate SAS Cabling
   For systems with external shelves (such as, ES40), confirm SAS cables are correctly connected and tested.

   • Data Domain: SAS Cable Configuration, Topology checks and Testing.

8. Check IPMI/iDRAC Power State
   Verify that the system is powered on.

   • Point a web browser to the iDRAC IP address and login to check the system status

9. Run adminaccess show over Serial
   If serial access is available, check for host restrictions that may block remote access.

10. Verify DDVE Network Settings
    For virtual appliances, inspect VM network settings and gateway configuration. Re-enable the network adapter if needed.

Next Steps if Issue Persists

• Upload a Support Bundle (SUB)
• Open a service request with Dell Technical Support