VixDiskLib_GetMetadataKeys API in VMware Virtual Disk Development fails with Insufficient buffer size error

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:
In the VMware Virtual Disk Development kit (VDDK) logs, you see entries similar to:

VixDiskLib: VixDiskLib_GetMetadataKeys: Retrieve metadata keys.
VixDiskLib: VixDiskLib_GetMetadataKeys: Insufficient buffer size (has 0, need 202): Error 24 at 4513.
VixDiskLib: VixDiskLib_GetMetadataKeys: Retrieve metadata keys.
VixDiskLib: VixDiskLib_ReadMetadata: Retrieve metadata value.

Environment

VMware Virtual Disk Development 1.2

Cause

When calling the VixDiskLib_GetMetadataKeys function with a buffer length of zero, the function computes how much buffer space is needed and returns VIX_E_BUFFER_TOOSMALL. The caller then allocates the appropriate sized buffer and calls VixDiskLib_GetMetadataKeys again.

This issue occurs due to the way in which the VixDiskLib_GetMetadataKeys API works.

Resolution

These messages can be safely ignored.