Date: Sat, 20 Oct 2007 12:26:01 -0700 From: Alfred Perlstein <alfred@freebsd.org> To: Oleg Derevenetz <oleg@vsi.ru> Cc: freebsd-stable@freebsd.org Subject: Re: kern/104406: [ufs] Processes get stuck in "ufs" state underpersistent CPU load Message-ID: <20071020192601.GW31826@elvis.mu.org> In-Reply-To: <006d01c8133a$674a90b0$eec55358@W2KOOOD> References: <027d01c8125c$73d4db80$c8c55358@delloleg> <20071019220501.GL31826@elvis.mu.org> <006d01c8133a$674a90b0$eec55358@W2KOOOD>
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* Oleg Derevenetz <oleg@vsi.ru> [071020 09:58] wrote: > > > Can anyone take a look on PR kern/104406 ? I got repeatable hang > situation, > > > but I can't obtain a kernel dump to get result of all show commands from > > > here: > > > > > > > http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneldebug-deadlocks.html > > > > > > After my break to debugger using Ctrl+Alt+Esc sequence and entering a > > > "panic" command kernel does not wrote a kernel dump but seems to hang. > Can > > > anyone describe how to obtain a kernel dump in this situation, or at > least > > > say - which output of show commands need in first place to debug this ? > > > Output of all suggested commands is huge and I afraid of making mistake > > > when carrying this output from screen to list of paper and back :-) > > > > Oleg, one thing you can do to make this less painful is to > > run your machine's console over serial port. > > > > First get a crossover serial cable, make sure it works from one > > box to another, it should be easy to run "tip com1" on both > > boxes to ensure that it works. > > > > Then you just need to add console=comconsole to /boot/loader.conf > > and your box's console should come over serial. > > > > Then on the machine watching the console, you can just do this: > > > > % script > > Script started, output file is typescript > > % tip com1 > > ...do ddb stuff now... > > ...stop tip > > % exit > > > > now you should have everything logged into a file called "typescript" > > should save you a big headache. > > Thanks, I'll try it in the monday morning. > > > As far as getting a dump from ddb, try this: > > > > ddb> call doadump > > > > I'm completely at a loss why this isn't a base ddb command "dump" > > but whatever... :) > > Unfortunately, this doesn't work too. I called duty personnel in this > datacenter and asked them to do this, and person on duty tells me that after > he enters this command something like that arrives on monitor: > > db> call doadump > Dumping 3072 MB > > Dump aborted error I/O > Dump failed. (Error 5) Hmnmm, that seems like you might be having a hardware problem, what disk device do you have? Have you also enabled kernel dumps via /etc/rc.conf:dumpdev= ? -- - Alfred Perlstein
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