For vSphere 6.7 U3 EP1 | Last document update: 12 October 2021
Check back for additions and updates to these release notes.
About the Virtual Disk Development Kit
The Virtual Disk Development Kit (VDDK) 6.7.3 EP1 is patch release based on partner demand. At time of release, it is the latest in the VDDK 6.7 series.
To perform proxy backup, VDDK 6.7.3 EP1 supports Red Hat Enterprise Linux (RHEL) 6.10, in addition to the operating systems supported in VDDK 6.7.3.
Changes and New Features
This release contains bug fixes and new features.
- NBD performance improvement for high-latency datastores
- Extended compatibility for VMware Cloud releases
- New Red Hat support, as above.
Compatibility Notices
This VDDK release is backward compatible with vSphere 6.0, vSphere 6.5, vSAN 6.6, vSAN 6.6.x, and vSphere 6.7.
ESXi hosts and especially any pre-6.7 vCenter Server should be upgraded in conjunction with VDDK libraries.
Recently Resolved Issues
The VDDK 6.7.0 EP1 release resolves the following issues:
- Configurable NFC AIO buffers.
In this release, users can configure asynchronous I/O buffers for NBD(SSL) transport. With high latency storage, backup and restore performance may improve after increasing NFC AIO buffer size. If servers are capable of high concurrency, backup and restore throughput may improve with more NFC AIO buffers. Defaults are buffer size 64K (1) and buffer count 4. NFC server memory consumption increases with larger NFC AIO buffer sizes and counts. Memory for each session can be calculated by multiplying buffer size * buffer count. If session memory exceeds 16MB, disk open operations will fail. In testing, these InitEx configuration file settings performed best, but this depends on hardware setup:
vixDiskLib.nfcAio.Session.BufSizeIn64KB=16
vixDiskLib.nfcAio.Session.BufCount=4 - CEIP phone home will report to Analytics Cloud.
For greater security assurance, the VDDK phone home facility (Customer Experience Improvement Program) now reports to the VMware Analytics Cloud (VAC) endpoint scapi.vmware.com, rather than directly to vCenter Server. If CEIP is enabled, customers might need to allow backup proxy access to scapi.vmware.com.
- Extended VMware Cloud (VMC) support.
VDDK 6.7.3 EP1 is being used with recent VMC releases, however VDDK 7.0 releases are recommended for best results with VMC.
Known Issues and Workarounds
This issue was reported by partners after the 6.7 release.
- NBD transport in VDDK 6.7 is slow when running against vSphere 6.5.
When data protection software is compiled with VDDK 6.7 EP1 libraries, NBD mode backup and restore is significantly slower than before on vSphere 6.5 or 6.0. This regression was caused by dropping the OPEN_BUFFERED flag when it became the default in VDDK 6.7. The OPEN_BUFFERED flag will be reintroduced in VDDK 6.7.1 for backward compatibility. When performance is important, VMware recommends use of NBD Asynchronous I/O, calling VixDiskLib_WriteAsync and VixDiskLib_Wait.
For issues in the VDDK 6.7 release, see the VDDK 6.7 Release Notes.
