Gentoo Archives: gentoo-user

From: John Covici <covici@××××××××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
Date: Fri, 17 Feb 2023 19:03:21
Message-Id: m38rgwxggo.wl-covici@ccs.covici.com
In Reply to: RE: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting by Laurence Perkins
1 On Thu, 16 Feb 2023 12:37:51 -0500,
2 Laurence Perkins wrote:
3 >
4 >
5 >
6 > >-----Original Message-----
7 > >From: John Covici <covici@××××××××××.com>
8 > >Sent: Wednesday, February 15, 2023 7:20 AM
9 > >To: gentoo-user@l.g.o
10 > >Subject: Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
11 > >
12 > >On Wed, 15 Feb 2023 09:50:27 -0500,
13 > >Grant Edwards wrote:
14 > >>
15 > >> On 2023-02-14, Rich Freeman <rich0@g.o> wrote:
16 > >>
17 > >> > Where are you getting this from, the system log/journal? This
18 > >> > doesn't seem like a clean shutdown, so if it is a kernel PANIC I
19 > >> > wouldn't expect the most critical info to be in the log (since it
20 > >> > will stop syncing to protect the filesystem). The details you need
21 > >> > probably will be displayed on the console briefly. You can also
22 > >> > enable a network console, which will send the dmesg output
23 > >> > continuously over UDP to another device. This won't be interrupted
24 > >> > by a PANIC unless there is some issue with the hardware or networking stack.
25 > >>
26 > >> If you've got a serial port[1], you could also set up serial logging.
27 > >> Though using serial ports have become a bit of a lost art, the serial
28 > >> console code in the kernel is pretty carefully designed to be the last
29 > >> man standing when things start to die. It's possible (though I
30 > >> wouldn't say probable) that a serial console will be able to show you
31 > >> stuff closer to the event horizon than a network console can.
32 > >>
33 > >> Anyway, since still I'm in the serial port business (yes, there are
34 > >> still plenty of people using serial ports in industrial settings) I
35 > >> had to mention it...
36 > >>
37 > >> [1] For this purpose you want a plain old UART on the motherboard type
38 > >> seial port. You'd be surprised how many motherboards still have
39 > >> them. Even though they're never brought out to a DB9 connector on
40 > >> the back panel, there's often an 8-pin header on the edge of the
41 > >> board somewhere, so you'd need one of these:
42 > >>
43 > >>
44 > >> https://www.amazon.com/C2G-27550-Adapter-Bracket-Motherboards/dp/B0002
45 > >> J27R8/
46 > >
47 > >I do have one which I use for my speech synthesizer. I also have one on my other box which I could hook up -- if I can find my null modem cable. I think I will try the netconsole first and the serial console if that does not work.
48 > >
49 > >Thanks for the hint.
50 > >
51 > >
52 > https://wiki.gentoo.org/wiki/Kernel_Crash_Dumps is another option if you're somehow not getting enough information out of the console. More complex to set up, but you can take an actual debugger to the result and hopefully find out exactly what's going on.
53
54 Well, some progress, but no joy. I found actual messages from
55 netconsole and it seems no matter what device I put for the source,
56 netconsole says it doesn't exist. I tried my eno1, and also eth0 and
57 eth1. In my normal boot sequence, I see that udev renamed eth1 to
58 eno1, but netconsole still said it does not exist. So, I may have to
59 use the serial console method, I have to find my cables for that. I
60 did also try to add net.ifnames=0 to my boot options, but no joy
61 there.
62
63 --
64 Your life is like a penny. You're going to lose it. The question is:
65 How do
66 you spend it?
67
68 John Covici wb2una
69 covici@××××××××××.com

Replies

Subject Author
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting Mark Knecht <markknecht@×××××.com>