Virtual Volume help

Greetings,

I have a virtual volume device driver and file system driver. The file system
and volume driver work well together when using both drive letters and mount
points. For the most part, NTFS and the volume driver work OK, but I’m
having trouble with mount points. The format command will not format
the volume device if mounted on a mount point (it complains about an
invalid drive letter). If I mount the volume on a drive letter, I can format
it with NTFS OK. Once formatted, I can then remount it on a mount
point and it functions OK. The volume driver is legacy style (not PnP),

In stepping through format.com with windbg, I think the problem is that
it calls GetVolumeInformation and the virtual volume is not recognized
as a NT volume. I guess it does not call this function if formatting via
a drive letter…

Any ideas as to how I can make my volume device accessible to
tools such as format when using mount points?

Thanks,
Robert