Apache Fails to Start Due to Mutex/Semaphore Errors (No space left on device)
Introduction When managing Apache HTTP Server (httpd) on a Linux-based system, encountering startup failures accompanied by errors such as Couldn’t create the authdigest-opaque mutex or No space left on device can indicate underlying issues with system-level semaphore limits. Apache may fail to start and log errors like the following: AH00023: Couldn’t create the authdigest-opaque mutex AH01760: failed