Subject: Re: klog message corruption?
To: Tyrel Beede <>
From: Manuel Bouyer <>
List: tech-kern
Date: 07/13/2001 20:25:47
On Thu, Jul 12, 2001 at 03:15:59PM -0700, Tyrel Beede wrote:
> I'm currently working on a little project which generates quite a bit of
> logging information to the klog device.  When I examine the log file
> generated by syslogd some of the messages are being entered into the log
> in an incomplete form.  An arbitrary amount of the beginning of the
> message will be missing.  I'm wondering if, perhaps, there is a buffer
> size I can adjust within the klog device or if this problem is related
> to syslogd.  Any suggestions are appreciated.  This problem seems to
> effect about, just roughly, 1 in every 50 messages.

From options(4):
     options MSGBUFSIZE=integer
     This option sets the size of the kernel message buffer.  This buffer
     holds the kernel output of printf() when not (yet) read by syslogd(8).
     This is particularly useful when the system has crashed and you wish to
     lookup the kernel output from just before the crash.  Also, since the au-
     toconfig output becomes more and more verbose, it sometimes happens that
     the message buffer overflows before syslogd(8) was able to read it.  Note
     that not all systems are capable of obtaining a variable sized message
     buffer.  There are also some systems on which memory contents are not
     preserved across reboots.

Manuel Bouyer <>