Status of support for Dynamic volumes and GPT disks under Windows

[apocryph]

The VDDK docs seem to imply that the 1.2 version of the VDDK includes support for Dynamic volumes like Simple, Spanned, Striped, and Mirrored, as well as volumes on GPT disks. It even seems the VixMntapi_OpenDiskSet API call was added for just this purpose.

However, in my tests this is not the case. I have a number of small VMDKs which I have formatted with various volume types with both MBR and GPT disk layouts. The only VMDKs which produce the expected result from the VixMntapi_GetVolumeHandles call are the MBR Basic disks. MBR Dynamic disks, and any GPT disk, fail to detect the volumes I have created on these disks.

Nothing in the log output produced by the logging callbacks indicates an error; it just returns either 0 volumes (in the case of the RAID disks) or 1 volume that is not the correct size or contents. I get the same erroneous results from vmware-mount.exe.

It's possible I'm doing something wrong, of course. What is the current status of GPT and MBR Dynamic support in the VDDK 1.2? Should what I'm attempting be successful? Has anyone else had luck getting any of this to work?

Thanks.

[admin]

Hi,

VDDK does not support GPT disks (nor RAID5). But Spanned, Striped or Mirrored disks should work (ie one can read from such volumes).

Can you point out where the docs say GPT disks are supported?

Vmware-mount supports only basic disks (there is no provision to specify multiple disks on the command line).

Thanks

Sudarsan

[apocryph]

Hi,

VDDK does not support GPT disks (nor RAID5). But Spanned, Striped or Mirrored disks should work (ie one can read from such volumes).

Can you point out where the docs say GPT disks are supported?

I got the impression from a few things in the VDDK 1.2 docs. One is on the Programmer's Guide (https://docs.google.com/viewer?url=http://www.vmware.com/support/developer/vddk/vddk12_api_programming.pdf) page 52 under Disk Volume Information lists the supported volume types as Basic Partition, GPT, Dynamic, and LVM.

Also on page 56 under File System Support mention is made of GPT volumes.

Any plans to add support for GPT disks? Newer machines with UEFI firmware get GPT disks by default under Windows 7, and our customers who require partition sizes in excess of 2TB have no choice but to use GPT.

Any suggestions for what might be preventing dynamic volumes from working for me?

[admin]

I do not know of any plans at this time for GPT support. If you have logs from the vixMntapi client, can you post them?

Thanks

Sudarsan