Note This content applies to the Windows Logo Kit (WLK). For the latest information using the new Windows Hardware Certification Kit (HCK), see Windows HCK User's Guide on the Windows Hardware Dev Center.


The VDS HCT test helps validate that the VDS H/W provider that is installed on the system is implementing the VDS interfaces according to the VDS specification.


The computer that is running this test must have a storage subsystem connected to it with a VDS H/W provider installed on it. Virtual Disk Service (VDS) will load the H/W provider that is installed on the system during the service startup. The API calls to the H/W subsystem will be routed to the H/W provider by VDS. The test communicates with the H/W Subsystem using the APIs implemented by VDS H/W provider and verifies that the provider is implementing the APIs according to the VDS specification and VDS Logo requirements.


The test loads VDS and queries VDS for the providers that are installed on the system. If it does not find any H/W provider on the system, the test quits immediately. If it finds a H/W provider, the test starts the appropriate tests based on the version and type of the provider.

Test Methodology

Each H/W provider implements a set of COM interfaces, depending on the type and version of the provider. Each of these interfaces implement one or more COM methods. The test determines the interfaces to be tested based on the provider type and sequentially calls tests for each interface that is applicable to the provider. Some of the interfaces might be optional according to the VDS specification and the test takes that into account while testing the interfaces.

Interface Tests

For each interface that is being tested, the test calls all of the methods of the interface with different parameter options.

The test verifies the following:

  • When good parameters are passed to the API, the API call returns success and works as expected.

  • When bad parameters are passed to the API, the API fails with appropriate error code.

  • For the objects created in the H/W provider, the test verifies that it adheres to the VDS Object model and COM consistency check.

  • The interaction between H/W provider and VDS service is correct. For example, a LUN that is provisioned on the subsystem and unmasked to the local system should appear as a disk on the system and LUN object and disk object should be associated with each other in VDS.


The test will report failures if any of the required interface or method is not implemented according to the specifications.

Results Interpretation

The log file that is generated will log the details of the error along with the line number of the failure and all of the variations that succeeded before the failure. This information and the VDS trace file can help identify the bug in H/W provider or VDS.

Run Time:

Log File:

System Restart Required:

Test Category:

Supported operating systems for Logo or Signature testing:

  • Windows Vista

  • Windows Server 2003



Software Requirements

The test tool requires the following software:

  • Supported operating system (see list above)

  • Software components included with the device that is being tested

Hardware Requirements

The test tool requires the following hardware:

  • Device to be tested

  • Computer that meets the minimum software requirements

  • Windows keyboard

  • Two-button pointing device

  • Color display monitor capable of at least 1024 by 768 resolution, 32-bits per pixel, 60 Hz

  • Hard drive with a minimum of 20 GB available on partition C:

  • VDS H/W provider should be installed on the system and system should be connected to the storage array


The test tool runs on the following processor architectures:

  • x86

  • x64

  • Itanium


In order for LUNs to be created or deleted during the test, we recommend that you have at least 10 GB of free drive space on the array available before running the test. The default LUN create size is 100 MB, and the test will create a couple of test LUNs.

Note This space is not visible as partition (on VDS software provider) unless the LUN is created and unmasked to WWN port.

Build date: 9/14/2012