According toofficial F5 documentation (K52015891 – Troubleshooting BIG-IP power supply issues),hardware-related alerts for power supplies, fans, and chassis components are logged in /var/log/ltm.
When a BIG-IP device experiences a power supply issue—such as failure, intermittent outages, or fan-related faults—the system generates alerts through internal platform monitoring services. These alerts are written to the/var/log/ltmfile and often appear with messages similar to:
Chassis power supply 2 has experienced an issue. Status is as follows: FAN=bad; STATUS=bad.
This makes /var/log/ltm theauthoritative log filefor identifying and verifying power supply and chassis-related problems on BIG-IP systems.
The other log files are not appropriate for this purpose:
/var/log/daemon.logcontains general daemon messages but isnot the primary sourcefor chassis hardware alerts.
/var/log/kern.loglogs kernel-level events, not platform power status.
/var/log/auditrecords administrative actions and configuration changes.
Conclusion:
Per F5-supported guidance, when suspecting power supply outages or chassis hardware issues, the BIG-IP Administrator shouldalways check /var/log/ltm first.
