A systems administrator is investigating a Linux server after receiving alerts that a critical web application has become unresponsive. The administrator discovers that the application has stopped writing new entries to its log file in /var/log/webapp/. Further investigation reveals that several other core system services are also failing to write to their respective log files in subdirectories under /var/log. Attempts to restart the failed services are unsuccessful. Which of the following is the MOST likely cause of these issues?
The web application's service account has incorrect write permissions on its log directory.
The /var partition has run out of disk space.
The system's rsyslog service has crashed and is not running.
A misconfigured firewall rule is blocking traffic to the logging service.
The correct answer is that the /var partition has run out of disk space. On many Linux systems, the /var directory is on its own partition and contains frequently changing data, including system logs (/var/log), package caches, and temporary files. When this partition becomes full, no new data can be written, which explains why multiple services, not just the web application, are unable to write to their log files. A full /var partition can also prevent services from starting, as they may need to write PID files or other temporary data to this location upon startup, which aligns with the observed service restart failures. An incorrect service account permission would typically only affect the single web application, not other system services. A crashed logging service like rsyslog would explain the logging failures but is less likely to cause other services to fail to restart. A misconfigured firewall would not prevent local processes from writing to local log files.