Date: Fri, 6 Aug 2010 16:04:18 -0700 From: Jeremy Chadwick <freebsd@jdc.parodius.com> To: Mark Saad <mark.saad@ymail.com> Cc: freebsd-stable@FreeBSD.ORG Subject: Re: Dumpdev issue in 6.4-STABLE Message-ID: <20100806230418.GA51617@icarus.home.lan> In-Reply-To: <915273.79945.qm@web35301.mail.mud.yahoo.com> References: <201008062231.o76MVEji063809@lurza.secnetix.de> <915273.79945.qm@web35301.mail.mud.yahoo.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, Aug 06, 2010 at 03:37:37PM -0700, Mark Saad wrote: > > Mark Saad wrote: > > > > wrote: > > > > > I then set in /boot/loader.conf > > > > > > > > > > dumpdev="/dev/da0s1b" > > > > > > > > On 8-STABLE dumpdev should be defined in rc.conf(5). > > > > Not sure about > > > > 6-STABLE offhand. > > > > > > The box dies before init is started so dumpdev in > > rc.conf is pointless. > > > > I'm afraid you can't set dumpdev from the loader. > > > > In ancient times it was possible to hardcode the dumpdev > > via the kernel configuration, but that option is long > > gone, AFAIK. > > > Oliver so how do I get a core file of what the kernel is doing ? What is the "new way" of doing this ? Use of dumpdev in /etc/rc.conf is utilised by /etc/rc.d/dumpon. This rc script runs /sbin/dumpon, specifying the device, which tells the kernel what device to dump stuff to using an ioctl() call for DIOCSKERNELDUMP. There doesn't appear to be a way to make an ioctl call from within DDB. I would say you're basically out of luck; someone on freebsd-hackers may know of a secret way. Otherwise I would say DDB needs to be extended to provide a "dumpdev" command or something along those lines which would do the ioctl() equivalent. You can drop to DDB interactively by pressing Control-Alt-Escape. You can examine the system state from there, but even "call doadump" probably won't work given that the kernel doesn't know what dump device to use (re: the ioctl() call above). -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20100806230418.GA51617>