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Configuring Null Tape Devices for Testing

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SummaryDPX/BEX supports the creation of virtual devices that emulate a tape device but discard the data. Such null devices are useful for testing performance and functionality.

This article describes a useful function.


Simulated backups can be sent to null devices. The data is read and transmitted to the device server as in a real backup, but the data is discarded instead of being written to tape. The full backup process is carried out, including adding Catalog data. Null devices are supported on all operating systems that are compatible with a full device server installation of DPX.

Use the following procedure:

  1. Add the null device in the Configure Devices windows in the management console as if it were a regular tape device.
  2. Add a new device cluster. To avoid confusion, use a descriptive name that indicates the device cluster is not real.
  3. Set the media type to a type not in use in your Enterprise.
  4. Add the devices for the appropriate node for testing purposes. Specify the device ID based on the operating system type as follows:

    Linux/UNIX: /dev/null
    Windows: \\.\null
    NetWare (BEX 3.2 or later): null

  5. Add a media pool of the same media type using the Configure Media window of the management console. Allocate sufficient media volsers for the planned testing. Disregard maximum passes, capacity, and other values, as they are unimportant for this purpose.
Note: For Windows and NetWare, the device ID is not case-sensitive, but each device ID must be unique within the DPX catalog. Additional null devices for the same node may be configured using a different case for the device ID (for example, \\.\Null and \\.\ NULL). For UNIX, the device ID is case-sensitive and must be the correct path to the null device on the UNIX system.

Note: Additional null devices may be configured for the same node if they are supported on the operating system as symbolic links to /dev/null; for example, ln -s /dev/null /opt/BackEx/bin/JB/newnull).

Note: In some cases NDMP backup performance investigation can involve checking of netapp controller and perform backup to NetApp null device: 

To perform a level 0 dump of volume vol0 to the NULL device, enter the following: dump 0f null /vol/vol0

Addtional Information
Article Number000003504
Article TypeTSN
Last Modified Date1/23/2017 3:20 PM
Created Date11/16/2016 8:32 PM



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