Troubleshooting Unexpected Reboots

Unexpected reboots are caused by one of two things – hardware problems, or FreeBSD kernel panics. The vast majority of the time it is hardware problems. Hardware diagnostics should be run before trying anything else.

If the reboot was caused by a kernel panic and the firewall has swap space available, the GUI will display a prompt asking to view the crash report. If there is no kernel panic, then the cause is most likely a hardware problem.

For hardware issues, check on:

  • Failing power supply

  • Flaky electricity in general

  • Overheating CPU

  • Overheating or faulty RAM

  • Faulty hard drive/SSD/other storage

  • Faulty drive cables

  • and many others…

If the firewall does panic, and the panic message contains a backtrace that mentions things like memory allocation, mbuf, uma_zalloc_arg, or similar, then it may be crashing due to mbuf exhaustion. See Tuning and Troubleshooting Network Cards for information on how to overcome that problem.

Devices with eMMC or small disks may not have any swap space and thus may not be able to recover panic information. In these cases they will typically print the panic information on the console when it occurs. If the device has a serial console, record the output there.

See also

See Obtaining Panic Information for Developers for details.