1. Introduction

Checkmk’s web-based, graphic user interface (GUI) has two functions:

  • It displays the current status of all hosts, services and events.

  • It is used to configure Checkmk. The relevant module is known as WATO.

A feature of Checkmk’s interface is that it can simultaneously display and configure multiple monitoring instances, and then perform like a large system. The following screenshot shows a Checkmk start screen directly after logging in:

user interface

Here you can see the following elements:


Your Checkmk installation’s version. Clicking on the version number opens a summary of updates for this version.


The Tactical Overview with the number of monitored hosts and services, any current problems, and the number of those problems that are unacknowledged. You can click on these numbers and receive a summary for each. Problems from services whose host is DOWN will not be included here!


An interactive field for searching for hosts and services. More about this later below …​


Views offers access to various displays of hosts, services and other information from the current monitoring.


On the sidebar’s lower edge there are three buttons: button sidebar addsnapin lo takes you to a selection of the elements available for the sidebar, button sidebar settings lo to your personal settings, and with button sidebar logout lo you can log out of the Checkmk interface.


In every page’s header you will find the name of the logged-in user, their role and the timestamp for the page’s last calculation or refresh.


Host Statistics shows the count of hosts in the various states — by number, and in a spatially true-to-scale graphic.


Service Statistics shows the services, as above for hosts


A list of all host problems that are currently unacknowledged. Clicking on the box’s title opens an enlarged view.


As for the unacknowledged service problems


Monitoring events recorded over the last four hours


Button to edit the dashboard

The dashboard on the right side can be customized. You can find our more in the article on dashboards.

2. The sidebar

The section on the left side — the sidebar — offers quick access to all of the functions in Checkmk. Some elements — e.g. the Tactical Overview — also show current status information so that you can continuously monitor it. If the sidebar doesn’t fit completely in your screen’s area you can scale it with the mouse wheel or by clicking on and dragging the dark area of an element up or down.

In addition, as a user you can easily customize the sidebar’s content. Elements can be…​

  • …​opened and closed with a click on the title bar,

  • …​repositioned by clicking and dragging on the title bar,

  • …​removed by clicking on the corner cross.

With the button sidebar addsnapin lo button you can access a selection of elements that are not currently in your sidebar, but which can be added with a simple click:

sidebar add snapin


user interface bookmarks

Bookmarks are an easy option in Checkmk for faster access to regularly-used pages. In the sidebar element Bookmarks, every page you can see on the right side can be saved as a bookmark. If you are on the desired paged or a filtered view that you would like to save, then click on Add Bookmark. The new bookmark will be stored in the My Bookmarks field. This field can be opened by clicking on the small arrow symbol.

3.1. Editing bookmarks

Checkmk manages bookmarks in lists. In addition, every bookmark has a Topic. In the display all bookmarks with the same topic are under one rubric where each can be expanded and collapsed. Why so complicated? So that you can make a list of bookmarks visible to other users. In this way, for your company you can build a navigation structure for specific views and even to external pages. Every user can nonetheless still manage their own bookmarks.

The EDIT button accesses the bookmarks manager:

user interface bookmark lists

You can either edit existing lists with icon edit, or create a completely new list with New list. The Title for a list in the General Properties is not important — it is only used for management. Via Make available for all users you can make the bookmark visible to all other users. This requires an permission however, which by default is held only by the Administrator role. This principle of visibility is used by Checkmk in many locations, and is explained in more detail in the views article.

user interface edit bookmark list 1

Where the bookmarks are sorted is decided by the Default topic in the list, or respectively by an individual bookmark’s Topic — if this has been set. By the way, you can also give bookmarks their own icons.

user interface edit bookmark list 2

4. Quicksearch

The Quicksearch snapin allows you to search for hosts and services using simple keywords or regular expressions. You will see the results live as you type them in a drop-down list below the search field. You can then use this list to call up the views of the elements found.

user interface quicksearch

In addition to the free search, you can also set and combine filters explicitly — for example, to search for specific services on specific hosts. A search coded with h:^myhost s:myservice will find all services that contain myservice and which run on hosts starting with myhost.

You can also use the filters multiple times and in combination. Multiple instances of a filter are linked with OR, different filters with AND. Exception: Multiple host tag filters (tg:) are always linked with AND. If you do not set any filters, the search automatically passes through the filters for host name, host aliases, host address, and service description — in that order. You can adjust the default filters and their order in WATO > Global Settings > User Interface > Quicksearch search order.

The following filters are available:






h: oracle

Service description




s: cpu h: myhost

Host group




hg: server hg: database

Service group




sg: testing s: myservice

Host address




ad: 192.168.200. s: test

Host alias




al: database al: _db

Host tag




tg: windows tg: testing

In combination with regular expressions, this results in precise, complex filter possibilities, such as h: ^My.Host$ s: ^my.(\d|test)$ tg: mytag tg: mytest. This would find: Services that begin with my and end with a digit or test, run on hosts that begin with my and end with host, and finally have the two host tags mytag and mytest.

You can use regular expressions for any single filter — but not for every combination. As soon as you set group or host tag filters in addition to host or service filters (name, address, alias), the former must be specified explicitly, for example hg: web server s: (apache|nginx). Accordingly, hg: Web.* s: (apache|nginx) does not work. Background: The different filters address different sources with different data structures and functions. However, as mentioned above, you can also search for specific host groups using patterns, hg: .*server, in order to use them in queries.

In the background, livestatus queries are created from these searches. For example, h: localhost s: mem s: cpu h:switch-intern would become:

OMD[mysite]:~$ lq
GET services
Cache: reload
Columns: service_description host_name hostgroups servicegroups
Filter: host_name ~~ switch-intern
Filter: host_name ~~ localhost
Or: 2
Filter: service_description ~~ cpu
Filter: service_description ~~ mem
Or: 2
And: 2
Limit: 80

CPU utilization;localhost;;
CPU load;localhost;;
CPU utilization;myhost;;
CPU load;myhost;;


You also see the value Limit: 80 in the live status query above. The drop-down list of the Quicksearch snapin is limited to these 80 hits by default. You can however adjust the value in WATO > Global Settings > User Interface > Number of elements to show in Quicksearch.

5. Themes

The GUI is available with three different themes: Modern, Modern (Dark) and Classic. The theme Modern is activated by default, as seen here in the screenshot.

user interface theme

However, you can alternatively switch to the old theme Classic, whose screenshots you might encounter in older and external articles.

To change the theme globally, open WATO > Global Settings, scroll to the User Interface area and click the Modern button next to the User interface theme option. In the subsequent dialog you can then select the desired theme.

user interface theme classic

Of course, you can also define themes individually for each user via WATO > Users. The option can be found respectively under Personal Settings > User Interface Theme. Users can also change themes themselves in their Personal Settings.

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