Avamar: Backup to Data Domain Fails with DDR Connection Errors

Avamar backups fail or complete with DDR exception errors. Common log entries include:

DDRInstance::Connect: Unable to connect to DDR: dell.ddr.com
ddp_connect_with_config() failed, Hostname: hostanme.com, Err: 5037-Cannot resolve IP address from Host failover.hostname.com
ddp_access() failed, Path ..., Err: 5004-nfs lookup failed (nfs: No such file or directory)
avtar Warning: API in exception state, rejecting API call DDR_DISCONNECT
Shutdown DDR communications manager, failed to close DDR handle, DDR result code: 4903
avtar Warning <10558>: shutdown DDR communications manager, failed to shutdown, DDR result code: 4903, desc: API call rejected.

Additional errors may also reference the following:

DDR_OPEN_MSTREAM
Unhandled API exception
Failed to create stream for file

The root cause is typically related to connectivity issues between the Avamar client and the Data Domain system. This may involve domain naming system (DNS) resolution failures, network configuration problems, or DD Boost communication errors.

• Verify DD Boost Connectivity

  • Run the ddpconnchk utility on the Windows client to test connectivity with the Data Domain system.
    • See Dell KB: Data Domain: DDPCONNCHK How to troubleshoot Data Domain DD Boost connectivity and performance. (Customer Login may be required)

• Check DNS and Network Configuration

  • Ensure that the client can resolve the Data Domain hostname and reach it over the network.
  • Confirm that firewall rules allow DD Boost traffic.

• Review Data Domain Settings

  • Validate that the Data Domain system is online and configured for DD Boost access.

• Escalate if Needed

  • If issues persist, engage Dell Support for advanced troubleshooting.