Hi,
When a disk object is detected in the IRP_MJ_PNP function of our disk filter driver we call IOCTL_DISK_GET_DRIVE_GEOMETRY_EX.
We pass in the buffer big enough for DISK_GEOMETRY_EX + DISK_PARTITION_INFO + DISK_DETECTION_INFO.
For Windows 2000 to Windows 2016 this has always worked but on Windows 2019 only the DISK_GEOMETRY_EX structure is returned initialised.
The number of bytes returned from the ioctl is 40 (the size of DISK_GEOMETRY_EX) compared with 112 for Windows 2016.
My debug system is a VMWare workstation but this also fails on vSphere and AWS Windows 2019 instances
The system boots using BIOS MBR rather than UEFI.
I have installed Windows 2019 Version 1809, Build 17763.253.
I have tried after turning off all Windows Defender settings I could find with no better result.
If anyone has any suggestions that would be greatly appreciated.
Thanks Sarah