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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!news.bhp.com.au!mel.dit.csiro.au!munnari.OZ.AU!news.hawaii.edu!ames!hookup!gatech!newsfeed.internetmci.com!tank.news.pipex.net!pipex!blackbush.xlink.net!zib-berlin.de!news.tu-chemnitz.de!irz401!uriah.heep!news From: j@uriah.heep.sax.de (J Wunsch) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Scanty details on almost crash? Date: 27 Jan 1996 21:21:44 GMT Organization: Private BSD site, Dresden Lines: 33 Message-ID: <4ee518$np9@uriah.heep.sax.de> References: <4e6ab3$ceo@mips.infocom.com> Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) NNTP-Posting-Host: localhost.heep.sax.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Newsreader: knews 0.9.3 josh@infocom.com (Josh Albertson) writes: > This may not be a FreeBSD problem just from the mere fact that I lack > details. I have twice experienced this. My pentium running FreeBSD 2.1 > seems to stop being interactive. I can ping it and get a response (it > has a direct net connect as you so guessed), but anything that requires a > shell on it in some form or another is a no go. The machine doesn't context-switch anymore. This is no good... The lower levels of the kernel (interrupt routines) are still alive, so you get ping responses and character echoes on the tty lines, but the processes are no longer scheduled for some reason. I've seen this most often when something in the disk subsystem went wrong, so the currently active process was stuck waiting for some disk IO that never finished. There might be other reasons as well, and it's unfortunately one of the hardest problems to track. If you're advanturous, you could setup a kernel with DDB. When the time has come and the machine is stuck again, hit the DDB hotkey on the console (by default Ctrl-Alt-ESC), and poke around. You've got a fully-functional `ps' command inside DDB, this might be a good start to find on which events the processes are waiting. Good luck! (Hint: put your console into a mode with as many lines as possible. This makes it easier to track DDB output.) -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)