Virtual Disk Development Kit FAQ

Frequently Asked Questions


1. What is the Virtual Disk Development Kit (VDDK)?

The VMware VDDK is an open API and SDK that help customers and ISV/IHV partners develop applications that create and access virtual disk storage. The VDDK enables partners (such as enterprise backup & recovery software vendors, anti-virus security vendors, and system management vendors) to extend their solutions to support virtualized IT environments and offer solutions for the virtualization market place.

2. What's new in VDDK 1.1?

VDDK 1.1 offers several important new features, including advanced transport for SAN and HotAdd, the Vix Mount API for remote mounting virtual disk, internationalization, 64-bit support, and SSPI authentication for Windows.

3. Why did VMware release the Virtual Disk Development Kit?

Industry standards and open interfaces and APIs for virtualization increase the availability of complementary solutions, provide more choices to the customer, and increase interoperability of virtualized IT environments. This expands the virtualization market, which is good for VMware. The VDDK will help VMware grow the virtualization market by enabling a new ecosystem of partners to build applications that create or access virtual disks.

4. What are some of the use-cases for virtual disk development Kit?

The VDDK provides easy access to virtual disk storage, enabling a wide range of use-cases for application vendors including:

  • Creation of virtual machine disk files to store backup of physical images
  • Read access to virtual disk, enabling off-line centralized anti-virus scanning of virtual machines
  • Write access to virtual disk, enabling off-line centralized patching of virtual machines
  • Read access to virtual disk, enabling off-line software package analysis of virtual machines

5. What is included in the Virtual Disk Development Kit?

The VDDK is a collection of C libraries and utilities, code samples, and documentation to help virtual disk storage. The kit includes:

  • The Virtual Disk library, a set of C function calls to manipulate VMDK files, the VMware virtual disk format
  • The Disk Mount library, a set of C function calls to mount and remote-mount VMDK file systems.
  • C++ code samples that may be compiled with either Visual Studio or the GNU C compiler
  • The Virtual Disk API Programming Guide, a PDF book introducing the Virtual Disk library
  • An online HTML reference for all function calls and error codes in the Virtual Disk API
  • The Virtual Disk Manager User's Guide, a PDF manual describing the vmware-vdiskmanager command
  • The VMware DiskMount User's Guide, a PDF manual describing the vmware-mount command

6. What VMware products are supported by Virtual Disk Development Kit?

The VDDK supports virtual disk format for VMware vSphere 4 (including ESX/ESXi), vCenter Server 4, VMware Virtual Infrastructure (ESX/ESXi 3 or 3.5 and VirtualCenter 2 or 2.5), VMware Server, VMware Workstation, VMware Player, and VMware Fusion products.

VDDK supports vCenter Server and VMware vSphere, including ESX/ESXi. The free ESXi version is not supported. When VDDK is embedded in a partner solution, VDDK licensing mandates the use of vSphere Foundation, Standard, or Enterprise products, not ESX/ESXi standalone.

7. What are the operating environment requirements?

Windows and Linux 32-bit and 64-bit versions are supported.

8. How does the Virtual Disk Development Kit benefit ISV/IHV partners?

ISV/IHV partners can leverage VDDK support to lower development costs, shorten time to market, enter new virtualization markets, and increase interoperability with virtualized IT environments. The VDDK enables ISV/IHV partners to develop complementary applications that work effectively across multiple virtual disks from a central location.

9. Is the Virtual Disk Development Kit redistributable?

Yes. To qualify for VDDK redistribution, you must be in the VMware TAP program at Select level or above and sign a redistribution agreement. Contact your VMware alliance manager to request the VDDK redistribution agreement. Please tell us how you plan to use the VDDK, in what products you plan to redistribute it, your company name, and contact information.

10. How does VDDK compare with vStorage APIs for Data Protection?

The vStorage APIs for Data Protection (VADP) is a backup framework that enables off-host, efficient, centralized backup and restore of vSphere virtual machines. The VDDK is focused on efficient access and transfer of data on virtual disk storage. It is one of the two key components of vStorage APIs for Data Protection. The VDDK can be used in conjunction with other key VADP component (vSphere SDK) as a framework to enable efficient backup and restore of vSphere virtual machines.

The VMware vSphere API is a Web Service and XML interface focused on management of virtual machines and ESX server configuration.

11. What are hosted disk and managed disk? Are both supported?

Hosted disk is virtual storage managed by a hosted product, such as Workstation, for a guest operating system. Managed disk is virtual storage managed by an ESX host or vCenter Server, contained within a VMFS volume. The VDDK supports both.

12. Does the Virtual Disk Development Kit support dynamic disks?

The Vix Mount API supports dynamic disk on Windows systems, although RAID 5 is not supported. However the vmware-mount program that is included in VDDK does not support dynamic disk on Windows systems.

The Vix Mount API does not support logical disk manager (LDM) on Linux systems.

Last updated 8 June 2009 5:00 pm