In ZK documentation, we have:
"The myid file consists of a single line containing only the text of that machine's id. So myid of server 1 would contain the text "1" and nothing else. The id must be unique within the ensemble and should have a value between 1 and 255."
This however is not enforced in code, which should be fixed either in documentation that we remove the restriction of the range 1-255 or in code we enforce such constraint.