Error Code [13:20] Failed to read chunk in media for storage policy copy

Article ID: AUXCP0021 The auxiliary copy operation fails when it is performed on a storage policy in which the primary copy is stored on a Data Domain device.


The auxiliary copy operation fails with any one of the following error message:

Error Code 13:20:
Failed to read chunk [...] in media [...] for storage policy [...] copy [...]:Backup job [...]. Encountered an I/O error while performing the operation


The errors occurs for one of the following reasons when using the Data Domain device:

  • The Data Domain is configured as Workgroup.
  • The account that is used to access the mount paths on the Data Domain device does not have rights assigned to the following default configuration path on the MediaAgents.

    C:\Program Files\Commvault\Simpana


If the Data Domain is not configured to authenticate user accounts by using Active Directory, complete these steps:

  1. Add the user or service account, which was used to configure the UNC/CIFS mount path for the Data Domain, to the local administrators group of the source and destination MediaAgents.
  2. Ensure that the user or service account has Full Rights to the software installation directory. Windows Vista, Windows 7, Windows 2008 or Windows 2008 R2 requires explicit rights to this folder, including all subfolders and files.

    To verify which user or service account is configured on the mount path, see Modify the Mount Path.

    Note: In the Connect As box, the user account is the account that must be added in the local administrators group.