Just found a bug in the "Clone Virtual Server" in virtualmin.
After the copy is done BIND configuration is broken.
The server copy has "DNS domain enabled?" UNCHECKED and in place of "DNS Records" there is an "Suggested DNS records" but the domain have configuration in /etc/named.conf and a .hosts file in /var/named/ But this hosts file includes only:
domain.com. IN A XXX.XXX.XXX.XXX
www.domain.com. IN A XXX.XXX.XXX.XXX
ftp.domain.com. IN A XXX.XXX.XXX.XXX
m.domain.com. IN A XXX.XXX.XXX.XXX
localhost.domain.com. IN A 127.0.0.1
webmail.domain.com. IN A XXX.XXX.XXX.XXX
admin.domain.com. IN A XXX.XXX.XXX.XXX
(names and IPs replaced here)
Which obviously is not valid configuration and on next restart BIND refuse to start complaining for missing TTL value.
p.s. the source domain have DNS enabled checked and valid DNS configuration.
p.s2 enabling DNS for domain - do not work ->already hosting DNS for this domain. Manually deleting the .hosts file and name.conf entry and check the DNS for domain tick generates the same broken configuration!