The kernel.printk specification in the /etc/sysctl.conf file specifies the kernel print logging specifications.

There are 4 values specified:

  • console loglevel. The lowest priority of messages printed to the console.

  • default loglevel. The lowest level for messages without a specific log level.

  • The lowest possible level for the console log level.

  • The default value for console log level.

There are eight possible entries per value.

  • define KERN_EMERG "<0>" /* system is unusable */

  • define KERN_ALERT "<1>" /* action must be taken immediately */

  • define KERN_CRIT "<2>" /* critical conditions */

  • define KERN_ERR "<3>" /* error conditions */

  • define KERN_WARNING "<4>" /* warning conditions */

  • define KERN_NOTICE "<5>" /* normal but significant condition */

  • define KERN_INFO "<6>" /* informational */

  • define KERN_DEBUG "<7>" /* debug-level messages */

Set the kernel.printk values to 3 4 1 7 and ensure that the line kernel.printk=3 4 1 7 exists in the /etc/sysctl.conf file.