Author Archives: Hermann Maurer

Migrate To AlmaLinux From CentOS 8 Using Almalinux-deploy Script

The article describes a way to move from Centos 8 to AlmaLinux. This is a hot topic because Centos 8 won’t be supported after December 2021 anymore.

Winter is Coming for CentOS 8

This article describes very good and deeply the problem with Centos 8 and also its evolution from the beginning to today, when everyone using Centos 8 should make (should have made!) thoughts about the future of his systems.

Fortigate checks in Check_MK

Dear friends of Check_MK and Fortigates,

I would like to clarify something related to Fortigate checks that I did maintain a long period of time. Those checks ran pretty well (from my point of view) and were useful in the versions of Check_MK before 1.4. Starting from 1.4 Check_MK has some strong Fortigate checks, which work quite well and those make the further development of my checks (almost) not reasonable anymore.

This is the reason, why I stopped maintaining my checks. Of course, I am still missing the check related to FAPs (Fortinet Access Points) and I don’t like the built-in VPN check very much (N tunnels from L are down).

So, please share your ideas with me and others in the comments, what kind of Fortigate checks you are missing in Check_MK 1.4 or what checks from my package you would like to see updated for Check_MK 1.4.

Best regards

Hermann Maurer

DELL Plugin for Check_MK updated to 1.3.1


I modified the package some weeks ago, The new version includes a check for temperature of each unit in a stack. I have uploaded the package to Check_MK Exchange site lately. It should become available after the verifitcation soon,

Kind regards

Hermann Maurer

A special Fortigate Check_MK plugin 2.3.1

Those of you who are suffered by the issue with duplicated service description, which is caused by a conflict of two different named checks: one built-in in Check_MK starting from 1.2.8 and one of mine.

This special version has other service descriptions and check names. The functionality is the same as in the version 2.3.

You can download the Check_MK package at the temporary place.

Update: After Robert had reported that the new version didn’t work under 1.2.8 and 1.4 versions of Check_MK, I have figured out that the plugin didn’t work (ran into an exception) because of a change between the versions 1.2.6 and 1.2.8 of Check_MK: the global variable nagios_state_names was renamed in core_state_names. Therefore I’ve created an updated version and am waiting for a confirmation, if this new version is working.

New Check_MK checks for DELL N-series switches


I have just uploaded a new package onto Check_MK Exchange. The package contains 2 checks for DELL N1500, N2000 and N3000 series switches. They check CPU utilization and RAM usage using SNMP requests. The checks have been created under 1.2.6 version of Check_MK and support this version.

After a verification by Check_MK staff the package can be downloaded from Check_MK Exchange web site.


Hermann Maurer

Fortigate Check_MK plugin updated to 2.3

Once again I have uploaded a new version of the Fortigate Check_MK plugin to Check_MK Exchange. The new version 2.3 got a new check called fortigate-wlan-info. This check is intended to display the following information about the usage of Fortiinet Access Points (FAP), connected to the monitored Fortigate:

  • Number of active FAPs
  • Numer of missed FAPs or those in down state
  • Numer of mobile clients connected to all FAPs

The new check has a Perf-O-Meter as well as an adjusted PNP4Nagios template.

The new vesion of the plugin can be (hopefully soon) downloaded from Check_MK Exchange.

Fortigate checks for Check_MK updated to 2.2.4

Hi there,

the only change is related to the check fortigate_mem. I have changed the evaluation of the parameters in the check. Now it’s possible to set warning and critical values in WATO. The old version did’t work and raised an exception.

I have uploaded the new version to Exchange of Check_MK. It should become available shortly.


Hermann Maurer

Retain changes in Netscaler 10.5 after reboot

If you have to do with Citrix Netscaler 10.5, you might have needed to change something on the installation, for example customize the layout of the authentication page. If you don’t take care a special way, your change will disappear after the next cold reboot of Citrix Netscaler. Continue reading