Checkmk differentiates between the configuration environment in which you manage the hosts, services and settings, and the actual monitoring in which the operational monitoring takes place.
Changes in the configuration — adding a new host, for example — will initially have no effect on the monitoring. Changes must first be enabled by an Activate Changes command, which will bring all changes that you have accumulated since the last activation command as a ‘bundle’ into the active production. This might seem a little cumbersome, but it does have the advantage that more complex changes can be prepared without haste in advance before being put into production. For example, after adding a new host you might want to define thresholds or remove some services before ‘arming’ the new component.
The tool for configuring Checkmk via GUI is called the WATO (Web Administration Tool). WATO maintains all configurations in a conventional text data format which experienced users can edit manually, or even create with scripts. WATO can be accessed via the corresponding element in the sidebar. This element is included as standard and offers direct access to all WATO modules.
Whenever you make a change to the monitoring configuration using WATO, this change will at first be picked up and held as pending. Such changes can be identified by the button in the WATO modules, and respectively the button in the sidebar. Both of these buttons open a list of the changes:
With the Activate Changes button the configuration data from WATO will be used to generate a new configuration for the monitoring core, and instruct the core to immediately begin using the new configuration:
The list of pending changes is subsequently cleared. These entries are not lost however — they can subsequently be called up with the Audit Log button. Here you can find a log file of all changes that have been made using WATO.
Over time, you will put a lot of work into the exact configuration of your hosts and services, limits, alerts and so on — so you should make backups. This is not only useful in case something goes wrong, but also for testing or using different configurations. You can back up the complete configuration using the WATO module Backups and restore it if necessary. Backups can be scheduled, encrypted and compressed.
2.2. Configuring encrypted compressed backups
In the first step you create a new backup target via WATO > Backups > Backup targets > New backup target. The absolute path specification refers to the system, not the instance.
Then, create a new key for your backups via with a meaningful name and a secure password.
Attention: After creating the key you will see a warning message telling you that you have not downloaded the keys yet. Since you need these keys to restore backups, the message will remain until all keys have been backed up.
Now you can create a new backup job via and among other things you can select the items you just created under Target or Encryption. You will also find options for compression and scheduling backups. As you soon will see, you can also trigger backups manually. With Do not backup historical data you can save metrics (RRD files), monitoring history and log files, which leads to significantly smaller backup archives.
2.3. Creating backups
Back on the start page of the backup module you can now see your finished backup job and start it via :
You can stop running backups with :
Finally, you will see the confirmation of the completed backup:
For both running and completed jobs, use to display a detailed status message.
2.4. Restoring backups
You can start restoring backups via , the procedure is largely self-explanatory:
Select the backup job.
Select the desired backup file.
Start and authorize the operation with the backup key.
After restoring, the instance is restarted, so you temporarily see a 503 error message:
As soon as the instance is available again you will receive a detailed status message about the successful backup:
3. Important WATO modules
WATO includes numerous modules — one for each important function of Checkmk. The following modules are particularly important:
A list of all WATO modules, each with a short description
Here you will find Checkmk agents for Linux, Windows and other operating systems. In the Enterprise Editions you can also configure, package and automatically update the agents via WATO.
Management of the hosts to be monitored — perhaps the most important module.
Global settings — those that do not apply to specific hosts, services or users.
Host & Service Parameters
All settings for specific hosts or services are found here. The configuration procedure is rule based.
4. Quick access
Once you have worked longer with WATO you will have learned its icons off by heart — then the smaller version of the WATO menu for the sidebar can be recommended: