cvs commit: src/sys/alpha/alpha support.s src/sys/i386/i386 swtch.s src/sys/kern kern_shutdown.c src/sys/sys systm.h

[Robert Watson]

On Tue, 20 Jan 2004, Don Lewis wrote:

> It would be extremely helpful to preserve the panic message and
> (optionally) the backtrace across the reboot.  Crash dumps may not
> always be possible for any number of reasons (swap smaller than RAM,
> /var/crash too small or overflowing with previous crash dumps, crash
> dump takes too long ...).  This is especially true in cases where the
> machine crashes and reboots unattended. 

Actually, I was having a very similar conversation with Bill Paul this
afternoon.  We were discussing dropping a copy of the kernel message
buffer onto the header of swap space on panic, if possible, and then
dropping them in /var/log/crash.log for management by newsyslog.  Then the
natural response to "My machine spontaneously reboots" becomes "Look for
something recent in /var/log/crash.log", as opposed to "You'll need to
enable crash dumps, set up a serial console", etc.  It's also something we
could turn on by default, as opposed to crash dumps, which would otherwise
consume of alot of disk space.

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert at fledge.watson.org      Senior Research Scientist, McAfee Research