Increasing the DMESG buffer....

[Ian Smith]

On Fri, 23 Nov 2012 11:33:21 +0100, Lars Engels wrote:
 > Am 23.11.2012 05:50, schrieb Ian Smith:
 > > On Thu, 22 Nov 2012 16:20:52 -0800, Kevin Oberman wrote:
[..]
 > >  > >> Also, isn't the entire verbose boot captured in /var/run/dmesg?
 > >  > >
 > >  > > Only if the message buffer hasn't overflowed before the utility runs
 > > to
 > >  > > populate the file
 > >  >
 > >  > Ouch! I did miss hte obvious. Thanks for pointing this out.
 > > 
 > > I've noticed quite a few truncated verbose dmesgs posted over the last
 > > couple of years, sometimes frustratingly starting after important stuff
 > > like the CPU info or ACPI tables etc .. Lars presumably had increased
 > > his buffer size to capture 85k, which would be well less than Adrian's
 > > suggested 64k with more minimal hda + pcm logging.  Perhaps a debug.snd.
 > > or something tunable could reenable the higher verbosity if/when needed?
 > 
 > 
 > No, I was creating the dmesg on a vanilla FreeBSD 10-CURRENT kernel and the
 > other one on PC-BSD 9.1-RCsomething.

Well that's interesting, excuse my assumption.  But as downloaded:
-rw-r--r--  1 smithi  smithi     82415 Nov 22 14:08 T61_dmesg.boot.10.works

So is the default msgbufsize on 10 different to what mav@ just posted?

 > kern.msgbufsize="65536" # Set size of kernel message buffer

And if the PC-BSD 9.1-RCsomething one you refer to is:
http://bsd-geek.de/FreeBSD/T61_dmesg.boot.9.works

then that's only 37844 bytes and has most of its head missing, in fact 
starting only a screenful before the hda stuff that's most of the rest.

cheers, Ian