Use this guide to install the latest RAW version of Check_MK.

• Configure your network.
• Configure NTP.
• Disable SELinux. Normally i would let SELinux be enabled, but with a monitoring system it is one of the few exceptions I make. This service does too many things SELinux doesn't like.
• Configure EPEL repository.
• Create a separate /opt filesystem.

• Install fonts (for RRD graphs):

  yum install dejavu-fonts-common dejavu-sans-mono-fonts dejavu-lgc-sans-mono-fonts

• Download the latest CRE (Check_MK Raw Edition) for CentOS 7.
• Install the CRE RPM:

  yum localinstall check-mk-raw-1.2.6p4-el7-34.x86_64.rpm

• Create a production site:

  # omd create prod
  Adding /opt/omd/sites/prod/tmp to /etc/fstab.
  Restarting Apache...OK
  Creating temporary filesystem /omd/sites/prod/tmp...OK
  Created new site prod with version 1.2.6p4.cre.
  
    The site can be started with omd start prod.
    The default web UI is available at http://monitor.mgmt.dc.polaire.nl/prod/
    The admin user for the web applications is omdadmin with password omd.
    Please do a su - prod for administration of this site.

• Start the prod site:

  omd start

• Configure the site:

  omd config

• Open the appropriate firewall ports (eg. port 80/443)

• Download the new version, for example: check-mk-raw-1.2.6p6-el7-34.x86_64.rpm
• Install the new version:

  rpm -ivh check-mk-raw-1.2.6p6-el7-34.x86_64.rpm

• Switch to site user (prod):

  su - prod

• Stop OMD:

  omd stop

• Update OMD, select the newer version:

  omd update

• Check versions:

  OMD[prod]:~$ omd versions
  1.2.6p4.cre
  1.2.6p5.cre
  1.2.6p6.cre (default)

• Start OMD:

  omd start

• Test!