Apache httpd restart fails with: Couldn't create the watchdog-callback mutex

Solution Verified - Updated -


  • Apache httpd fails to startup with the following error:

    [Mon May 14 03:40:04.013122 2018] [core:emerg] [pid 29108:tid 140509184628480] (28)No space left on device: AH00023: Couldn't create the watchdog-callback mutex
    [Mon May 14 03:40:04.016950 2018] [:emerg] [pid 29108:tid 140509184628480] AH00020: Configuration Failed, exiting


  • Red Hat Enterprise Linux (RHEL)
    • 6
  • Red Hat JBoss Core Services (JBCS)
    • 2.4.23 SP3
  • Apache Web Server (httpd)
    • < 2.4.25-3

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