I'm using HP-UX.
Basically the problem is I need another logical volume to test EVFS. At the moment, I can't add another physical volume to the sever. And it seems that all of the physical volume on the server is allocated to be mounted at root. As far as I know, I can't reduce the root logical volume. Which means I have to create a logical volume within the root logical volume.
In Linux, I'd create a loop device, then pvcreate, vgcreate, lvcreate with it, but HP-UX doesn't support loop devices.
Is there a solution to this?
Here's a image of vgdisplay on my system.

As you can see, the size of lvol_evfs1 I tried to create has a size of 0.