[Release] Checkmk stable release 1.6.0p21

Dear friends of Checkmk,

the new stable release 1.6.0p21 of Checkmk is ready for download.

This maintenance release ships with 25 changes affecing all editions of Checkmk,
1 Enterprise Edition specific changes and 0 Managed Services Edition specific changes.

Changes in all Checkmk Editions:

Checks & agents:

  • 12005 FIX: Agent Azure: Deal with over 1000 resources
  • 11433 FIX: Cluster discovery: Fixed bug with overlapping clusters
  • 11845 FIX: Eliminated a possibility of the Windows crash when Windows agent terminates updater
  • 11904 FIX: Fix TypeError in docker_container_diskstat check
  • 11901 FIX: Fix crash in ESX Inventory
  • 11903 FIX: Fix crash in hearbeat CRM general
  • 11724 FIX: check_sql: Encoding error in “Check SQL Database” rule
  • 11829 FIX: esx_vsphere_counters_diskio: IOPS
  • 11947 FIX: fileinfo: SAP HANA files shown as WARN if jointly monitored with other files
  • 11352 FIX: iptables: Keep ACK after update/restart
  • 11353 FIX: k8s_daemon_pods: Handle null value
  • 11525 FIX: lnx_if: Treat only interfaces with UP and LOWER_UP (bracket info from ip address) as UP
  • 11893 FIX: mk_errpt.aix: avoid escaping issues when ‘/’ is in errpts output
  • 11745 FIX: mssql_counters.file_sizes: convert all performance data to bytes
  • 11746 FIX: mssql_counters.file_sizes: return performance data for warn/crit values in bytes
  • 11895 FIX: omd_info: only create host label ‘cmk/check_mk_server:yes’ if sites are present
  • 11782 FIX: ups_out_load check and discovery crash on empty values for load and voltage
  • 11743 FIX: mk_logwatch: log files with special characters are ignored or cause crash
    NOTE: Please refer to the migration notes!

Core & setup:

  • 11868 FIX: mkbackup: Fix permission issues when backing up different sites

Event console:

  • 11744 FIX: support case-insensitive hostname matching for multiple host match types

HW/SW inventory:

  • 12117 FIX: Inventory: docker: Readd labels for images and containers

Other components:

  • 12030 FIX: NagVis: Updated to 1.9.24


  • 11397 FIX: Fix Service discovery when service checkoutput has values of -inf
  • 11434 FIX: WATO pages with host links: Fixed recently introduced performance problem

User interface:

  • 11789 SEC: Update jQuery to 3.5.1 to fix XSS vulnerability

Changes in the Checkmk Enterprise Edition:

Agent bakery:

  • 11726 FIX: Error on windows agent update in case of a numerical agent hash

Changes in the Checkmk Managed Services Edition:


You can download Checkmk from our download page:

Please mail bug reports and qualified feedback to feedback@checkmk.com.
We greatly thank you for using Checkmk and wish you a successful monitoring,

Your Checkmk Team