where's the full copy of dmesg(8)?

[Chris H]

> Chris H wrote this message on Sun, Mar 30, 2014 at 01:28 -0700:
>> Greetings, Adam, and thank you for your reply.
>> > On 03/29/2014 21:37, Chris H wrote:
>> >> Greetings,
>> >>  I'm testing on 9.2-STABLE, and was experimenting on an AMD sempron
>> >> (140). Booting from the boot-only, or DVD-1 DVD's doesn't emit the
>> >> entire dmesg(8) output. Building, and installing a custom kernel also
>> >> didn't provide the full dmesg(8) output.
>> >> Specifically; it omits the top N lines (N = as yet, undetermined Number).
>> >> I have no idea why, or how to correct this. I'm pretty confident
>> >> the processor, and motherboard (MSI) are not too new for FreeBSD.
>> >
>> > I am almost certain you want to increase kern.msgbufsize at the boot
>> > loader before booting.
>> >
>> > % sysctl -d kern.msgbufsize
>> > kern.msgbufsize: Size of the kernel message buffer
>>
>> Interesting. Given that every system I run has (default) value of 65536.
>> Can you, or anyone suggest what the correct, of better value should be?
>> Or better, what the formula to determine that value is? I'm not finding
>> either of those answers in the man(1) pages, or the documentation.
>>
>> Thanks again, for your thoughtful reply.
>
> Well, you're booting w/ bootverbose set, which is why you're running
> out of dmesg space... choosing a default that doesn't waste memory is
> hard, because some systems have complicated PCI bus layouts and many
> devices, that you'd have to set it very large to be fine for all
> systems, and that would be a waste on 99% of them...
>
> If you do find a system where a normal (non-bootverbose) boot cannot
> fit in dmesg, let us know...

Thank you for the reply.
Indeed. I boot verbose on all the systems. Yet they all appear to have
a large enough window to provide the top of the boot messages. Given
that this was 9.x (others are releng_8). I thought perhaps there was
a difference that caused this /apparent/ anomaly. There is a "noisy"
message regarding miibus0 (32 additional lines) that appears to be
a complaint. So I can easily see where this would have pushed the
top of the message buffer out of the window.
In the end, not having an "official" formula. I simply bumped the
window size by 512, until I got the information (messages) I would
normally expect to see.

Thank you very much for taking the time to respond.

--Chris

>
> Thanks.
>
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>
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