On Apr 5, 2012 16:12 "Camaleón" <noelamac@gmail.com> wrote: > You can send the output to another machine using a serial cable and instructing the kernel to dump the message there. I had to do this years > ago to debug a kernel crash from a VM but to be sincere, I doubt I can nowadays repeat that milestone, I don't remember the steps :-) > > Look, Ubuntu has some good doc about this: > > Kernel Debugging Tricks > <https://wiki.ubuntu.com/Kernel/KernelDebuggingTricks> > > Thank you for this reference! It is indeed an awesome reference. I tried getting netconsole to work, because I don't have a serial-to-USB cable. I will be looking into this problem over the next few days. Perhaps I will have to buy such a cable. There is also, according to the InitramfsDebug Debian wiki page, a way to get log data in /dev/.initramfs/initramfs.debug. I can not make this work either, for some reason. I tried the boot_delay option, but the delay seems to revert to full speed at a certain point in the boot sequence, so it is no use. There is odd behavior when the crash happens: The visible screen area seems to "scroll back" so that when the hang occurs, the timestamps show approximately 64.xxxxxx seconds (but actually, the crash occurs at 68.xxxxxx seconds). On a hunch, I tried setting acpi=off - and now the new kernel boots! Of course, this is a sub-optimal solution, so I got dmesg listings from both the old and the new kernel. The diff is here: http://pastebin.com/L4YXTmJh I would be very grateful if you'd take a look. Thanks, Lars
On Apr 5, 2012 16:12 "Camaleón" <noelamac@gmail.com> wrote:You can send the output to another machine using a serial cable andThank you for this reference! It is indeed an awesome reference. I tried getting netconsole to work, because I don't have a serial-to-USB cable. I will be looking into this problem over the next few days. There is also, according to the InitramfsDebug Debian wiki page, a way to get log data in /dev/.initramfs/initramfs.debug. I can not make this work either, for some reason.
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