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RHEL 10 compatible Distributions Cron Behavior When Updating Checkmk Crontabs

RHEL 10 compatible Distributions Cron Behavior When Updating Checkmk Crontabs

RHEL, Almalinux, Rocky & Oracle Linux 10 introduce a new cron behavior that automatically backs up crontab during Checkmk site updates, which results in harmless informational messages that can be safely ignored.

APPLICABLE TO ALL CHECKMK VERSIONS

Table of Contents

Overview

When operating Checkmk sites on RHEL 10 compatible distributions, administrators may notice new messages appearing during site start and stop operations. These messages indicate that a backup of the previous crontab has been created. This behavior is caused by changes in the operating system cron utility and not by Checkmk itself.

While running an  omd stop the system triggers cron updates for the site user. On RHEL 10 compatible distributions, the cron package has introduced a safety feature that automatically backs up crontabs whenever they are replaced. This leads to messages such as:

root@mylinuxhost:~$ omd stop mysite Backup of mysites's previous crontab saved to /omd/sites/mysite/.cache/crontab/crontab.bak OK Stopping apache...killing 15728.................OK Stopping nagios.....OK Stopping ui-job-scheduler...killing 15665...OK .......

 

Why this happens

RHEL 10 compatible distributions ship with a newer version of the "cronie" cron-daemon. This version introduces a feature that automatically creates a backup each time a crontab is updated or deleted. Older versions of RHEL 10 compatible distributions did not include this feature. Debian and Ubuntu also do not use this cron variant and therefore do not show these messages.

 

Previous behavior

  • In older RHEL 10 compatible distribution versions, the crontab utility overwrote files silently.

  • Administrators did not receive notifications regarding backups.

 

Current behavior

  • The crontab utility automatically creates a backup before replacing the file.

  • A notification message is printed each time Checkmk updates a crontab.

 

Can this message be ignored?

Yes. The message is informational only and does not require any administrative action. It simply confirms that the operating system created a backup before Checkmk replaced the crontab.
Checkmk has no sensible way of modifying this behavior, hence we document and accept it.

 

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