Re: finding cause of reboot

On Thu, Oct 16, 2025 at 8:12 AM Alan Somers <asomers@freebsd.org> wrote:

> The "boot" command will give you a vague description like "shutdown" or
> "crash".
>

boot command? I don't have this on my system. How do yo uget that?


> If a crash was the cause then maybe your system isn't configured to make
> core dumps.  I suggest forcing a crash with "sysctl debug.kdb.panic=1"
> while you watch the screen to see what happens.
>

Yea. If it is a reboot, and crash dumps are enabled, and there's nothing is
in /var/log/messages, you have limited options.

If there's a BMC, and it speaks IPMI, there might be something in the IPMI
log if it was hardware triggered (ipmitool sel list):
   1 |  Pre-Init  |0000001024| Processor #0xe4 | Presence detected |
Asserted
   2 |  Pre-Init  |0000000000| System Event | OEM System boot event |
Asserted
   3 |  Pre-Init  |0000000001| System Event | Timestamp Clock Sync |
Asserted
   4 | 04/17/23 | 16:07:49 MDT | System Event | Timestamp Clock Sync |
Asserted
   5 | 04/17/23 | 16:11:12 MDT | OS Boot #0x22 | boot completed - device
not specified | Asserted
   6 | 04/17/23 | 16:20:42 MDT | System Event | OEM System boot event |
Asserted
   7 | 04/17/23 | 16:23:16 MDT | System Event | OEM System boot event |
Asserted
   8 | 04/17/23 | 16:28:44 MDT | System Event | OEM System boot event |
Asserted
   9 | 04/17/23 | 16:30:25 MDT | OS Boot #0x22 | boot completed - device
not specified | Asserted
...
(oh my, I need to clear my log)

Warner

> On Thu, Oct 16, 2025 at 7:35 AM void <void@f-m.fm> wrote:
>
>> Hi,
>>
>> I'm trying to work out why a reboot is happening.
>> line power is fine. PSU is fine.
>> There's no coredump.
>> Nothing in /var/log/messages console.log all.log or daemon.log
>>
>> Is there a thing I can set somewhere which when enabled will
>> capture why a system reboots?
>>
>> thnx
>> --
>>
>>