Few weeks ago I received information about the VHDMount Tracing tool we added to the VHDMount into Virtual Server 2005 R2 SP1. I wanted to share with you how you can use this tracing functionality to see when something goes wrong when trying to mount a VHD file.
In case you are facing any failures please do following
1) set VHD_MOUNT_TRACE=2 (on command prompt)
2) Download and run DbgView.exe from http://www.microsoft.com/technet/sysinternals/utilities/debugview.mspx
3) This will create trace messages in DbgView.
VHD_MOUNT_TRACE=1 will output trace on console. Trace messages are appended by [Info][Warning][Error][Internal], which can be used to redirect it to file
VHD_MOUNT_TRACE=2 will output trace on debugger (kd / DbgView)
VHD_MOUNT_TRACE=3 will output trace on console and debugger both
If this env variable is not set, by default trace will only print Warning and Error messages on debugger.