How to find subdomain of a tld?

Answer 1

After setting up a development server, I'd like to create a subdomain devel.mydomain.tld on my real server.
First I tried to add a new zone in the DNS admin which didn't work. Now I manually created a subdomain in /var/named/mydomain.tld.db:

code:...
$ORIGIN devel.mydomain.tld.
devel.mydomain.tld. IN MX 10 mail.devel.mydomain.tld.
mail.devel.mydomain.tld. 14400 IN A 62.254.10.121
www.devel.mydomain.tld. 14400 IN A 62.254.10.121


This seems to work fine, but the new records don�t appear in DA and when. After changing something in the mydomain.tld etry, the subdomain is gone.