Date: Fri, 26 Jul 1996 22:09:39 +0200 (MET DST) From: Stefan Esser <se@zpr.uni-koeln.de> To: Cat Okita <cat@uunet.ca> Cc: "Marc G. Fournier" <scrappy@ki.net>, Stefan Esser <se@zpr.uni-koeln.de>, jkh@freebsd.org, current@freebsd.org, stable@freebsd.org, dg@root.com Subject: Obtaining a kernel core with NCR Message-ID: <199607262009.WAA00324@x14.mi.uni-koeln.de> In-Reply-To: <Pine.SUN.3.93.960722182751.24159F-100000@troll.uunet.ca> References: <Pine.NEB.3.94.960722175748.1614G-100000@ki.net> <Pine.SUN.3.93.960722182751.24159F-100000@troll.uunet.ca>
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Cat Okita writes: > > > 4) does it always hang ? > > Everytime it crashes, yes...doing reboot from the console > > has never hung it... > > *Only* when it crashes - a planned reboot, be it remote or local always seems > to work. Well, I just thought it might be a good idea to let you know, whether your system suffers form the same hang in the kernel dump code as mine. If you can afford the time to test this, I'd really appreciate receiving your results! The test requires a kernel compile a few more minutes of time for a the actual test. It does not cause a corrupt or dirty file system to be left over. (The FS is mounted R/O in single user mode anyway). 1) build a kernel with options "SCSI_DEBUG_FLAGS=DEBUG_SCATTER" options DDB 2) boot this kernel into single user mode 3) enter the command "dumpon /dev/sd0b" if you did not already define the dump device on the "config kernel" line in the config file 4) enter DDB by pressing CTL+ALT+ESC or CTL+Print depending on your keyboard (this is for syscons, don't know about PCVT) 5) enter the command "panic" at the debugger prompt. You will see a lot of trace output flow by, and it will stop with the well-known SCSI hang. My guess is, that the physical address of the last memory page touched is in the BIOS region. Please let me know what actual addresses (virtual and physical) there are at the start of the last scatter/gather block reported. Regards, STefan
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