NetWorker: Data Domain Device Mount Fails with Error 5520

Summary: Mounting or creating a Data Domain (DD) device in NetWorker may fail with error code 5520 if Retention Lock (RL) is not enabled and the system attempts to modify a retention-locked file. This issue is linked to an unexpected value in the global encryption setting on the DD system. ...

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Symptoms

Device mount or creation fails with the following error:

  • Err 5520: Cannot delete or modify a retention-locked file.

        
Cause

        
The failure occurs because the global encryption strength setting on the Data Domain system is incorrectly capitalized. NetWorker expects specific lowercase values, and mismatches can trigger retention lock-related errors during device operations.

  
Example of incorrect configuration:

  
    
   
  • 
    
    # ddboost option show
Option                          Value
------------------------------  -------
global-encryption-strength      Medium
    • 
  

  

        
Resolution

        
Update the encryption setting to use the correct lowercase value. Acceptable values are:

  
    
   
  • none
    • 
   
  • medium
    • 
   
  • high
    • 
  

  
To correct the setting:

  
Run the following command on the DD system:

  
    
   
  • 
    
    ddboost option set global-authentication-mode none global-encryption-strength medium
    • 
  

  
This change ensures compatibility with NetWorker operations and resolves the mount failure.

  


            


        

        
        
Affected Products

        NetWorker Family, NetWorker
    
Products

        Data Domain







                        

                            

    

        

            

                
                    
 Article Properties

                
            

            

                

                        
Article Number: 000381991

                

                
                

                        
Article Type: Solution

                

                

                        
Last Modified: 22 Oct 2025


                

                    

                            
Version:  1

                    


            


        

    

    

        

            

                
                    
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