How the diskspace feature works (filesystem housekeeping)

Owned by Marcel Schulte
Last updated: Nov 17, 2023 by Matthew Hierholzer
In the global settings of Checkmk, you can configure how the instance should do filesystem housekeeping (delete files by age, regarding abandoned hosts, or in case of filesystem running out of space).

LAST TESTED ON CHECKMK 2.1.0P1

Table of Contents

Configuration

The setting is named "Automatic disk space cleanup" and has these options:

  • Delete files older than
    Used to configure the age of files that should be deleted automatically - not set by default (factory settings)

  • Delete additional files when disk space is below
    Used to configure minimum free disk space before deleting files and lets you configure the age of files to keep (not to be deleted) - not set by default (factory settings)

  • Cleanup abandoned host files older than
    Used to configure when to delete files of abandoned hosts - set by default (factory settings) to 30 days so that these files get deleted 30 days after the host has been removed from monitoring

Setup → General → Global settings → Automatic disk space cleanup

Screenshot of cleanup abandoned host files older than option within global settings

Automatic execution

You do not have to configure the execution of this manually; every Checkmk instance user has a cronjob for the diskspace feature, which gets executed  5 minutes after each hour.

Which files are handled?

When started manually or automatically by a cronjob, the diskspace command behaves like this:

  1. read in configuration (set in global settings)

  2. load plugins from ~/share/diskspace

  3. load custom plugins from ~/local/share/diskspace, if existent - yes, you can define additional plugins yourselves

  4. collect paths and time information of all paths defined in loaded plugins

  5. delete files according to configured settings


Beware that "Cleanup abandoned host files older than" only handles completely missing hosts, not specific missing services, whereas the other two settings would also remove left service files.