[summary] Re: Reasonable/sane limits for kern.msgbufsize?

From: David Wolfskill <david_at_catwhisker.org>
Date: Thu, 08 Sep 2022 11:03:39 UTC
On Thu, Sep 01, 2022 at 04:36:44PM -0700, David Wolfskill wrote:
> ...
> How much trouble am I asking for if I set
> 
> kern.msgbufsize=262144
> 
> in /boot/laoder.conf?
> ...

I received a couple of responses from folks who had increased
kern.msgbufsize by a fair amount (to 204800 & 1MB, respectively) since 
several years ago, with no ill effects attributable to that.

As I already had a shell script I use to control rebooting (e.g.,
whether or not to boot verbosely; from which slice to boot), I
merely augmented that script so that if I'm requesting a verbose
boot, I also set things up to increase kern.msgbufsize "appropriately"
(and reset to default if I'm requesting a non-verbose boot).

This is probably a bit conservative, but it seems to be working for me
-- and /var/run/dmesg.boot gets the full boot log, even for a verbose
boot, which was the intent.

Ref. the (recent) "dmesg" links on
https://www.catwhisker.org/~david/FreeBSD/history/, such as
https://www.catwhisker.org/~david/FreeBSD/history/freebeast.14_dmesg.txt

Peace,
david
-- 
David H. Wolfskill                              david@catwhisker.org
"In my administration, I'm going to enforce all laws concerning the
protection of classified information. No one will be above the law."
 -- D. Trump, August, 2016

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