Subject: Anyone using i386 w/ MSGBUFSIZE > 512K?
To: None <email@example.com, firstname.lastname@example.org>
From: Ross Patterson <Ross.Patterson@CatchFS.Com>
Date: 04/18/2003 18:07:00
Since upgrading a few systems from 1.5 to 1.6, we're seeing something really
weird - gigantic runs of 0xFF in /var/log/messages. As best we can figure
out, attempts to read the kernel's message log (via /dev/klog (i.e. syslogd)
and sysctl(KERN_MSGBUF) (i.e. dmesg)) are actually returning these bytes,
about 1.5MB of them in one big chunk. We run with options
MSGBUFSIZE=2097152, so that leaves 512KB of readable data in the log buffer.
Have we hit some undocumented limit? "man 4 options" doesn't mention one, and
a day or so of reading things like kern/subr_log.c, arch/i386/i386/machdep.c
and arch/i386/i386/pmap.c haven't done anything except convinced us we don't
know what's going on with the kernel log. :-)
Ross A. Patterson
Chief Technology Officer
CatchFIRE Systems, Inc.
5885 Trinity Parkway, Suite 220
Centreville, VA 20120