On 4/10/19 8:23 AM, Simon Matter via CentOS wrote:
Hi,
For the last ten years or so, I've defined the short hostname in
/etc/hostname and the FQDN in /etc/hosts. Now I wanted to double-check
this information, which eventually led me to this page:
*
https://serverfault.com/questions/331936/setting-the-hostname-fqdn-or-short-name
Now I admit I'm even more confused than before.
Is there some reliable piece of information on this subject for CentOS ?
IMHO for those having proper DNS in place, the hostname should be set to
the FQDN in whatever place it is supposed to be set. I quite feel there is
something wrong if the only place where the FQDN is listed is the
/etc/hosts file.
I'm not very happy with how the issue was handled in Linux and the
different distributions in the last decades. Not to mention the
inconsistency in the relevant man pages.
Well, I am unhappy for about as long about /etc/hosts and how name
resolution "should" happen which it doesn't, namely, if
/etc/nsswitch.conf says
hosts: files dns
then ideally /etc/hosts should be used first, then nameservers. However
(and this is true both for Linux and FreeBSD), some commands never look
into /etc/hosts (e.g., command host), whereas some do use /etc/hosts
(e.g., command ping).
Valeri
I found the info mentioned in the FreeBSD man pages quite helpful even if
it has to be "translated" to Linux. See the excerpt of the mentioned man
pages below. If you believe this is heresy to be posted here, please don't
read it :-)
Regards,
Simon
----%>-------------------------------
root@freebsd:~ # man hostname
HOSTNAME(1) FreeBSD General Commands Manual
HOSTNAME(1)
NAME
hostname - set or print name of current host system
SYNOPSIS
hostname [-f] [-s | -d] [name-of-host]
DESCRIPTION
The hostname utility prints the name of the current host. The
super-user
can set the hostname by supplying an argument; this is usually done in
the initialization script /etc/rc.d/hostname, normally run at boot time.
This script uses the hostname variable in /etc/rc.conf.
...
root@freebsd:~ # man rc.conf
RC.CONF(5) FreeBSD File Formats Manual
RC.CONF(5)
NAME
rc.conf - system configuration information
DESCRIPTION
The file rc.conf contains descriptive information about the local host
...
hostname (str) The fully qualified domain name (FQDN) of this host on
the network. This should almost certainly be set to
something meaningful, even if there is no network connection.
If dhclient(8) is used to set the hostname via DHCP, this
variable should be set to an empty string. Within a jail(8)
the hostname is generally already set and this variable may
absent. If this value remains unset when the system is done
booting your console login will display the default hostname
of "Amnesiac".
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
https://lists.centos.org/mailman/listinfo/centos
--
++++++++++++++++++++++++++++++++++++++++
Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247
++++++++++++++++++++++++++++++++++++++++
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
https://lists.centos.org/mailman/listinfo/centos
