For now, the vfs.fs.discovery item returns:

• {#FSNAME}

  which is the mount point of the FS (eg C: or /var)

• {#FSTYPE}

  which is the type of filesystem

It would be greate to return a 3rd macro

which could contain the block device backing the filesystem. On Windows systems, it wouldn't be that usefull (it'll return the same thing as #FSNAME) but on UNIX systems, it could be used to create vfs.dev.read and vfs.dev.write item prototypes (returning something like /dev/sda1, /dev/vg_host/lv_root etc...)