A BIG-IP Administrator suspects that one of the BIG-IP device power supplies is experiencing power outages. Which log file should the BIG-IP…

According to official 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/ltm file 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 the authoritative log file for 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.log contains general daemon messages but is not the primary source for chassis

hardware alerts.

/var/log/kern.log logs kernel-level events, not platform power status.

/var/log/audit records administrative actions and configuration changes.

Conclusion:

Per F5-supported guidance, when suspecting power supply outages or chassis hardware issues, the

BIG-IP Administrator should always check /var/log/ltm first.