Um die Dom0 des XenServers mit cehck_mk überwachen zu können, muss man ein paar Änderungen am XenServer-Host vornehmen.

yum --enablerepo=base -y install xinetd

xinetd Konfiguration in /etc/xinetd.d/check_mk anlegen:

[root@defiant check_mk]# cat /etc/xinetd.d/check_mk 
# +------------------------------------------------------------------+
# |             ____ _               _        __  __ _  __           |
# |            / ___| |__   ___  ___| | __   |  \/  | |/ /           |
# |           | |   | '_ \ / _ \/ __| |/ /   | |\/| | ' /            |
# |           | |___| | | |  __/ (__|   <    | |  | | . \            |
# |            \____|_| |_|\___|\___|_|\_\___|_|  |_|_|\_\           |
# |                                                                  |
# | Copyright Mathias Kettner 2014             mk@mathias-kettner.de |
# +------------------------------------------------------------------+
#
# This file is part of Check_MK.
# The official homepage is at http://mathias-kettner.de/check_mk.
#
# check_mk is free software;  you can redistribute it and/or modify it
# under the  terms of the  GNU General Public License  as published by
# the Free Software Foundation in version 2.  check_mk is  distributed
# in the hope that it will be useful, but WITHOUT ANY WARRANTY;  with-
# out even the implied warranty of  MERCHANTABILITY  or  FITNESS FOR A
# PARTICULAR PURPOSE. See the  GNU General Public License for more de-
# ails.  You should have  received  a copy of the  GNU  General Public
# License along with GNU Make; see the file  COPYING.  If  not,  write
# to the Free Software Foundation, Inc., 51 Franklin St,  Fifth Floor,
# Boston, MA 02110-1301 USA.
 
service check_mk
{
	type           = UNLISTED
	port           = 6556
	socket_type    = stream
	protocol       = tcp
	wait           = no
	user           = root
	server         = /usr/local/bin/check_mk_agent
 
	# If you use fully redundant monitoring and poll the client
	# from more then one monitoring servers in parallel you might
	# want to use the agent cache wrapper:
	#server         = /usr/local/bin/check_mk_caching_agent
 
	# configure the IP address(es) of your Nagios server here:
	only_from      = 127.0.0.1 10.17.1.3
 
	# Don't be too verbose. Don't log every check. This might be
	# commented out for debugging. If this option is commented out
	# the default options will be used for this service.
	log_on_success =
 
	disable        = no
}

Anschließend muss man den xinet-Dienst noch dauerhaft aktivieren und auch starten:

systemctl enable xinetd
systemctl restart xinetd

In /etc/sysconfig/iptables die Zeile

   -A RH-Firewall-1-INPUT -m conntrack --ctstate NEW -m tcp -p tcp --dport 6556 -j ACCEPT

einfügen und die FW neu starten: service iptables restart

(Auf Monitoring Server) /opt/omd/versions/1.20/share/check_mk/agents/check_mk_agent.linux
(Auf Monitoring Server) /opt/omd/versions/1.20/share/check_mk/agents/check_mk_caching_agent.linux

Am besten nach /usr/local/bin, ohne .linux, muss zur Einstellung in der xindetd-Konfig oben passen!