Hmm, I must been blind :/
But now I get this, even if it used in the director.
Starting Varnish: varnishmgt_child_inherit(3, storage_file)
Unused backend child_2, defined:
(/usr/local/etc/main.vcl Line 6 Pos 9)
backend child_2 {
--------#######--
VCL compilation failed
.
/ E