FSLogix, way to see what is really there?

Question

Hi all,

FSLogix is a file system driver that seems to reside between the disk and the OS. It is designed to make Windows and applications on top of Windows all see things that are not really there. The directory C:\Users\<Username> that is there, doesn't really exist, since it is made up of the mounted FSLogix profile + the contents of the directory C:\Users\local_<username>.

That's fine. It's just that sometimes you have a need to check what is really there on disk. E.g., when using Treesize to check what is happening with the disk space on your RDS or Citrix host, the application isn't able to give you an accurate account of what space is used in the C:\Users directory, because it counts the C:\Users\<username> directory as if it were really there. The contents of an FSLogix profile is added to the count and the contents of the C:\Users\local_<username> is actually counted twice, since Treesize encounters that data twice, once in C:\Users\<username> and a second time in C:\Users\local_<username>.

Is there any way to circumvent the file system driver for a specific application, make it run in a special environment where it can really see what's on disk without being fooled by the file system driver? (without taking the server offline...)

Answer 1

You can mount the VHDX on any Windows machine/VM. Then add a drive letter to it. From then you can run treesize and do other things. When you're done detach the VHDX. Of course it can't be in use when you do this.

Answer 2

Thanks Martijn. But I was actually talking about working around the file system driver to see what is actually on the C-drive of the host, not what is inside the VHDX.