Virtual Disk Development Kit Release Notes

Release date: 14 MAR 2017 | Builds: ESXi 5146846, VDDK 5136645
VDDK 6.5.0b for vSphere 6.5b. Last document update: 13 APR 2017
Check frequently for additions and updates to these release notes.


About the Virtual Disk Development Kit

The Virtual Disk Development Kit (VDDK) 6.5.0b is an update to resolve customer issues. Here is its download page.

VDDK is used with vSphere Storage APIs for Data Protection (VADP) to develop backup and restore software. For general information about this development kit, how to obtain the software, programming details, and redistribution, see the VDDK documentation landing page.

VDDK 6.5 was tested with the following operating systems to perform proxy backup:

  • Windows Server 2012 and 2012 R2
  • Windows Server 2008 R2
  • Windows 10
  • Red Hat Enterprise Linux RHEL 6.7, 6.8, and 7.2.
  • SUSE Linux Enterprise Server SLES 11 SP4 and 12 SP1.

Changes and New Features

This release contains bug fixes but no new features, although NBD is a significant fix.

Compatibility Notices

ESXi hosts and especially vCenter Server should be upgraded in conjunction with VDDK libraries.

Recently Resolved Issues

The VDDK 6.5.0b release resolves the following issues:

  • NBD transport was quietly switched to slower NBDSSL mode.

    The VDDK 6.5 release forced NBD transport mode to use SSL encryption, making it in effect NBDSSL mode. Customers and partners complained that this caused slower performance. This release contains a fix to allow continued use of unencrypted NBD. Encrypted virtual machines can be backed up using NBD transport.

  • VDDK 6.5 had XML library 2.9.2 instead of more secure 2.9.4 version.

    Partners noticed that although the VDDK 6.5 open sources licenses file listed libxml2 version 2.9.4, the development kit actually contained version 2.9.2, which has known security vulnerabilities. This packaging error is fixed in this release.

Known Issues and Workarounds

The VDDK 6.5.0b release has the following known issues:

  • This release has an added dependency on the LZMA library.

    VDDK 6.5.0b (build 5136645) modified the DiskLibVim, XML, and gvmomi shared libraries to depend on the compression library liblzma, which is missing from the RHEL 6.8 Linux distribution. When is not found in the default library path, runtime failures for libvixDiskLibVim result. The workaround is to install this library on your backup proxy.

  • Disk clone is not supported for vCenter Server.

    The VixDiskLib_Clone function can be used to transfer hosted disk from VMware Workstation to managed disk on an ESXi host. In previous releases, it could be run on ESXi hosts, but not on the vCenter Server. A fix has been found to permit running VixDiskLib_Clone on vCenter Servers, but is not yet implemented in this patch release.

For more issues in the VDDK 6.5 release, see the VDDK 6.5 Release Notes.