VDDK 6.7 released. Update your backup solution!

Last week, VMware released a new version of their Virtual Disk Development Kit (VDDK) which makes it possible for developers to access and mount virtual disk files.

Its versioning generally follows vSphere versioning, so VDDK 6.7 was released to support new features of vSphere 6.7. It was also tested with vSphere 6.5 and 6.0 and it fixes some issues of the (now obsolete) VDDK 6.5 so you should definitely switch to 6.7 if you utilize one of the previous versions.

Please note that VDDK quietly resides inside virtually every backup solution for vSphere out there — Acronis, Veeam, VMcom ... you name it. So you might be using it every day without even knowing, which makes it worthwhile to update your backup software as soon as they implement the new kit.

VMcom Backup has already released a new version 6.7.10, others should follow soon.

Modifying your code

In order to use the new features in your homebrew application, some minor changes need to be done.

First of all, the old method of specifying the connection parameters has been deprecated. So instead of this...

VixDiskLibConnectParams cnxParams = {0};
cnxParams.port = 443;
cnxParams.nfcHostPort = 902;

... you are now supposed to utilize the VixDiskLib_AllocateConnectParams function.

VixDiskLibConnectParams *cnxParams = VixDiskLib_AllocateConnectParams();
cnxParams->port = 443;
cnxParams->nfcHostPort = 902;

The old method still works but you'll get a warning message and won't be able to utilize the 6.7 features.

Querying allocated blocks

To obtain a list of blocks actually allocated by a thinly-provisioned virtual disk, you are now encouraged to use a new function VixDiskLib_QueryAllocatedBlocks instead of QueryChangedDiskAreas with the asterisk parameter.

VixError
VixDiskLib_QueryAllocatedBlocks(VixDiskLibHandle diskHandle,
                                VixDiskLibSectorType startSector,
                                VixDiskLibSectorType numSectors,
                                VixDiskLibSectorType chunkSize,
                                VixDiskLibBlockList **blockList);

The new method is not only faster with large virtual disks, but furthermore it finally does not rely on changed block tracking anymore and works with NFS datastores too.

Conclusion

I believe these changes bring good news to everyone. If nothing else, we should get faster and more reliable backups. And that is good, isn't it?