Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On Thu, 16 Feb 2023 12:37:51 -0500, Laurence Perkins wrote: > > > > >-Original Message- > >From: John Covici > >Sent: Wednesday, February 15, 2023 7:20 AM > >To: gentoo-user@lists.gentoo.org > >Subject: Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting > > > >On Wed, 15 Feb 2023 09:50:27 -0500, > >Grant Edwards wrote: > >> > >> On 2023-02-14, Rich Freeman wrote: > >> > >> > Where are you getting this from, the system log/journal? This > >> > doesn't seem like a clean shutdown, so if it is a kernel PANIC I > >> > wouldn't expect the most critical info to be in the log (since it > >> > will stop syncing to protect the filesystem). The details you need > >> > probably will be displayed on the console briefly. You can also > >> > enable a network console, which will send the dmesg output > >> > continuously over UDP to another device. This won't be interrupted > >> > by a PANIC unless there is some issue with the hardware or networking > >> > stack. > >> > >> If you've got a serial port[1], you could also set up serial logging. > >> Though using serial ports have become a bit of a lost art, the serial > >> console code in the kernel is pretty carefully designed to be the last > >> man standing when things start to die. It's possible (though I > >> wouldn't say probable) that a serial console will be able to show you > >> stuff closer to the event horizon than a network console can. > >> > >> Anyway, since still I'm in the serial port business (yes, there are > >> still plenty of people using serial ports in industrial settings) I > >> had to mention it... > >> > >> [1] For this purpose you want a plain old UART on the motherboard type > >> seial port. You'd be surprised how many motherboards still have > >> them. Even though they're never brought out to a DB9 connector on > >> the back panel, there's often an 8-pin header on the edge of the > >> board somewhere, so you'd need one of these: > >> > >> > >> https://www.amazon.com/C2G-27550-Adapter-Bracket-Motherboards/dp/B0002 > >> J27R8/ > > > >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. > > > >Thanks for the hint. > > > > > 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. Second try, don't know what happened. So, after not getting any results from net console and somehow my null modem cable only seemed to work from another computer to the one with the problem kernel, I am trying to figure out how to set up for getting a crash dump. When looking at the article, it seems to want a root partition -- I use zfs, which automatically detects the root partition, so can I just forget about that one? Also I am using systemd, so there is no /etc/local.d, but I do have another location where I put commands to run after everything else has run -- do I put the start up script there? Also, there is a file /etc/conf.d/kexec.conf and I got a notice to move it to /etc/kexec.conf, what do I put there? -- Your life is like a penny. You're going to lose it. The question is: How do you spend it? John Covici wb2una cov...@ccs.covici.com
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On Thu, 16 Feb 2023 12:37:51 -0500, Laurence Perkins wrote: > > > > >-Original Message- > >From: John Covici > >Sent: Wednesday, February 15, 2023 7:20 AM > >To: gentoo-user@lists.gentoo.org > >Subject: Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting > > > >On Wed, 15 Feb 2023 09:50:27 -0500, > >Grant Edwards wrote: > >> > >> On 2023-02-14, Rich Freeman wrote: > >> > >> > Where are you getting this from, the system log/journal? This > >> > doesn't seem like a clean shutdown, so if it is a kernel PANIC I > >> > wouldn't expect the most critical info to be in the log (since it > >> > will stop syncing to protect the filesystem). The details you need > >> > probably will be displayed on the console briefly. You can also > >> > enable a network console, which will send the dmesg output > >> > continuously over UDP to another device. This won't be interrupted > >> > by a PANIC unless there is some issue with the hardware or networking > >> > stack. > >> > >> If you've got a serial port[1], you could also set up serial logging. > >> Though using serial ports have become a bit of a lost art, the serial > >> console code in the kernel is pretty carefully designed to be the last > >> man standing when things start to die. It's possible (though I > >> wouldn't say probable) that a serial console will be able to show you > >> stuff closer to the event horizon than a network console can. > >> > >> Anyway, since still I'm in the serial port business (yes, there are > >> still plenty of people using serial ports in industrial settings) I > >> had to mention it... > >> > >> [1] For this purpose you want a plain old UART on the motherboard type > >> seial port. You'd be surprised how many motherboards still have > >> them. Even though they're never brought out to a DB9 connector on > >> the back panel, there's often an 8-pin header on the edge of the > >> board somewhere, so you'd need one of these: > >> > >> > >> https://www.amazon.com/C2G-27550-Adapter-Bracket-Motherboards/dp/B0002 > >> J27R8/ > > > >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. > > > >Thanks for the hint. > > > > > 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. So, since I could get nothing out of the net console (it kept saying that the device was not found) and my null modem connection between the computer and another box only seemed to work from the box to the computer with the problem but not the other way, I am trying to set up to get a crash dump. A few questions about this -- my root partition is zfs, whereas the article seems to use /dev/something for the root. I am using systemd, so what do I need in /etc/kexec.conf --do I put all my kernel boot parameters in that file? -- Your life is like a penny. You're going to lose it. The question is: How do you spend it? John Covici wb2una cov...@ccs.covici.com
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
My problem is that the sender aborts netconsole, so there is nothing to receive. On Fri, 17 Feb 2023 15:13:52 -0500, Mark Knecht wrote: > > [1 ] > On Fri, Feb 17, 2023 at 12:03 PM John Covici wrote: > > > Well, some progress, but no joy. I found actual messages from > > netconsole and it seems no matter what device I put for the source, > > netconsole says it doesn't exist. I tried my eno1, and also eth0 and > > eth1. In my normal boot sequence, I see that udev renamed eth1 to > > eno1, but netconsole still said it does not exist. So, I may have to > > use the serial console method, I have to find my cables for that. I > > did also try to add net.ifnames=0 to my boot options, but no joy > > there. > > > > -- > > Your life is like a penny. You're going to lose it. The question is: > > How do > > you spend it? > > > > John Covici wb2una > > cov...@ccs.covici.com > > John, >I did a bad job at trying to point you in this direction the other day, > and in my testing I'm not sure how well it works. However another > option you might investigate is on the receiving end you can > apparently set the transmitter's IP address by using the > transmitter's mac address. Supposedly you would execute > something like the following, with extra spaces added > for readability: > > sudo arp -s 192.168.86.244 90:e6:ba:10:a3:e7 temp > > which supposedly says 'when you see a packet with this > mac address associate it with this IP address'. The temp > part says don't add it to the permanent tables. > > After executing this you are supposed to be able to use tools > that filter by IP address but I didn't have great results. > > Hope this helps, > Mark > [2 ] -- Your life is like a penny. You're going to lose it. The question is: How do you spend it? John Covici wb2una cov...@ccs.covici.com
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On Fri, Feb 17, 2023 at 12:03 PM John Covici wrote: > Well, some progress, but no joy. I found actual messages from > netconsole and it seems no matter what device I put for the source, > netconsole says it doesn't exist. I tried my eno1, and also eth0 and > eth1. In my normal boot sequence, I see that udev renamed eth1 to > eno1, but netconsole still said it does not exist. So, I may have to > use the serial console method, I have to find my cables for that. I > did also try to add net.ifnames=0 to my boot options, but no joy > there. > > -- > Your life is like a penny. You're going to lose it. The question is: > How do > you spend it? > > John Covici wb2una > cov...@ccs.covici.com John, I did a bad job at trying to point you in this direction the other day, and in my testing I'm not sure how well it works. However another option you might investigate is on the receiving end you can apparently set the transmitter's IP address by using the transmitter's mac address. Supposedly you would execute something like the following, with extra spaces added for readability: sudo arp -s 192.168.86.244 90:e6:ba:10:a3:e7 temp which supposedly says 'when you see a packet with this mac address associate it with this IP address'. The temp part says don't add it to the permanent tables. After executing this you are supposed to be able to use tools that filter by IP address but I didn't have great results. Hope this helps, Mark
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On Thu, 16 Feb 2023 12:37:51 -0500, Laurence Perkins wrote: > > > > >-Original Message- > >From: John Covici > >Sent: Wednesday, February 15, 2023 7:20 AM > >To: gentoo-user@lists.gentoo.org > >Subject: Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting > > > >On Wed, 15 Feb 2023 09:50:27 -0500, > >Grant Edwards wrote: > >> > >> On 2023-02-14, Rich Freeman wrote: > >> > >> > Where are you getting this from, the system log/journal? This > >> > doesn't seem like a clean shutdown, so if it is a kernel PANIC I > >> > wouldn't expect the most critical info to be in the log (since it > >> > will stop syncing to protect the filesystem). The details you need > >> > probably will be displayed on the console briefly. You can also > >> > enable a network console, which will send the dmesg output > >> > continuously over UDP to another device. This won't be interrupted > >> > by a PANIC unless there is some issue with the hardware or networking > >> > stack. > >> > >> If you've got a serial port[1], you could also set up serial logging. > >> Though using serial ports have become a bit of a lost art, the serial > >> console code in the kernel is pretty carefully designed to be the last > >> man standing when things start to die. It's possible (though I > >> wouldn't say probable) that a serial console will be able to show you > >> stuff closer to the event horizon than a network console can. > >> > >> Anyway, since still I'm in the serial port business (yes, there are > >> still plenty of people using serial ports in industrial settings) I > >> had to mention it... > >> > >> [1] For this purpose you want a plain old UART on the motherboard type > >> seial port. You'd be surprised how many motherboards still have > >> them. Even though they're never brought out to a DB9 connector on > >> the back panel, there's often an 8-pin header on the edge of the > >> board somewhere, so you'd need one of these: > >> > >> > >> https://www.amazon.com/C2G-27550-Adapter-Bracket-Motherboards/dp/B0002 > >> J27R8/ > > > >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. > > > >Thanks for the hint. > > > > > 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. Well, some progress, but no joy. I found actual messages from netconsole and it seems no matter what device I put for the source, netconsole says it doesn't exist. I tried my eno1, and also eth0 and eth1. In my normal boot sequence, I see that udev renamed eth1 to eno1, but netconsole still said it does not exist. So, I may have to use the serial console method, I have to find my cables for that. I did also try to add net.ifnames=0 to my boot options, but no joy there. -- Your life is like a penny. You're going to lose it. The question is: How do you spend it? John Covici wb2una cov...@ccs.covici.com
RE: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
>-Original Message- >From: John Covici >Sent: Wednesday, February 15, 2023 7:20 AM >To: gentoo-user@lists.gentoo.org >Subject: Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting > >On Wed, 15 Feb 2023 09:50:27 -0500, >Grant Edwards wrote: >> >> On 2023-02-14, Rich Freeman wrote: >> >> > Where are you getting this from, the system log/journal? This >> > doesn't seem like a clean shutdown, so if it is a kernel PANIC I >> > wouldn't expect the most critical info to be in the log (since it >> > will stop syncing to protect the filesystem). The details you need >> > probably will be displayed on the console briefly. You can also >> > enable a network console, which will send the dmesg output >> > continuously over UDP to another device. This won't be interrupted >> > by a PANIC unless there is some issue with the hardware or networking >> > stack. >> >> If you've got a serial port[1], you could also set up serial logging. >> Though using serial ports have become a bit of a lost art, the serial >> console code in the kernel is pretty carefully designed to be the last >> man standing when things start to die. It's possible (though I >> wouldn't say probable) that a serial console will be able to show you >> stuff closer to the event horizon than a network console can. >> >> Anyway, since still I'm in the serial port business (yes, there are >> still plenty of people using serial ports in industrial settings) I >> had to mention it... >> >> [1] For this purpose you want a plain old UART on the motherboard type >> seial port. You'd be surprised how many motherboards still have >> them. Even though they're never brought out to a DB9 connector on >> the back panel, there's often an 8-pin header on the edge of the >> board somewhere, so you'd need one of these: >> >> >> https://www.amazon.com/C2G-27550-Adapter-Bracket-Motherboards/dp/B0002 >> J27R8/ > >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. > >Thanks for the hint. > > 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. LMP
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On Thu, Feb 16, 2023 at 9:08 AM John Covici wrote: > > hmmm, but what should I use for the source ip, I only assign those > when I bring the interface up when I start the interface -- I have > something like this: > [Unit] > Description=Network Connectivity for %i > ... > So, before I run this, I don't think the card has any ip address, does > it? So, "cards" don't have an IP address. The kernel assigns an IP address to an interface, which is entirely a software construct. It happens to be a software construct that the network console feature largely ignores anyway. I didn't go reading the source code, but I'm guessing it is just constructing raw UDP packets and it will happily set the IP to whatever you want it to be. After all, it is just a field on the packet. So you can make the source IP whatever you want it to be. Just expect the packets to show up with the IP you set on them. There is no connection, so the IP doesn't need to be reachable by anything else. You could stick literally anything in there as long as some firewall isn't going to object and drop the packet. The destination IP matters because that is where it is going to go, and the interface matters because if it gets sent out on the wrong interface then obviously it won't make it there. I have no idea if the netconsole packets get seen by netfilter, but if this is on some kind of router that might be something you need to check, because if netfilter is configured to drop unassociated UDP from the firewall to the LAN that could be an issue. However, it is possible this just bypasses netfilter entirely. If you have the dynamic netconsole option enabled you could have a script update the settings after your network is up to set the source IP to the one assigned by DHCP and make sure it is on the right interface. As you point out though at boot time the interface won't have an IP. It won't even be "up," not that this is likely to bother the kernel. -- Rich
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
address=192.168.0.1 netmask=24 broadcast=192.168.0.255 So, before I run this, I don't think the card has any ip address, does it? >From what you hope the receiving machine arp -a ? HTH, Mark
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On Thu, 16 Feb 2023 07:11:12 -0500, Rich Freeman wrote: > > On Thu, Feb 16, 2023 at 6:50 AM John Covici wrote: > > > > The sending computer has two nics, eno1 for the internal network and > > eno2 is on the internet. So, my netconsole stanza said > > netconsole=@192.168.0.1/eno1,@192.168.0.2 > > Is CONFIG_NETCONSOLE enabled for your kernel? > > I'm not sure if the kernel will assign the names eno1/2 to interfaces > - I think those might be assigned by udev, which probably won't have > run before the kernel parses this instruction. You might need to use > eth0/1 - and your guess is as good as mine which one corresponds to > which. > > If it isn't one of those it might not hurt to put the target mac > address in there just to be safe. I haven't needed that but maybe > there are situations where ARP won't work (it would be needed if you > are crossing subnets, in which case you'd need the gateway MAC). Keep > in mind that this is a low-level function that doesn't use any > routing/userspace/etc. It was designed to be robust in the event of a > PANIC and to be able to be enabled fairly early during boot, so it > can't rely on the sorts of things we just take for granted with > networking. > > > > > The box which is at 192.168.0.2 has netcat (windows version) and I > > tried the following: > > netcat -u -v -l 192.168.0.2 and I also tried 192.168.0.1 > > which is the ip address of the linux console which I am trying to > > debug. > > > > I also tried 0.0.0.0 which did not work either, but I think the > > windows firewall was blocking, and I did fix that, but did not try the > > 0.0.0.0 after that. > > > > So I'm pretty sure that netcat requires listing the destination IP, > since it has to open a socket to listen on that IP. You can > optionally set a source address/port in which case it will ignore > anything else, but by default it will accept packets from any source. > > I was definitely going to suggest making sure that a windows firewall > wasn't blocking the inbound connections. That's fairly default > behavior on windows. hmmm, but what should I use for the source ip, I only assign those when I bring the interface up when I start the interface -- I have something like this: [Unit] Description=Network Connectivity for %i Documentation=man:ip Before=network.target Wants=network.target BindsTo=sys-subsystem-net-devices-%i.device After=sys-subsystem-net-devices-%i.device [Service] Type=oneshot RemainAfterExit=yes EnvironmentFile=/etc/conf.d/network@%i ExecStart=/bin/ip link set dev %i up ExecStart=/bin/ip addr add ${address}/${netmask} broadcast ${broadcast} dev %i ExecStart=-/bin/bash -c "test -n ${gateway} && /bin/ip route add default via ${gateway}" ExecStart=-/bin/bash -c "test -f /etc/conf.d/postup@%i.sh&&/bin/bash -c /etc/conf.d/postup@%i.sh" ExecStop=/bin/ip addr flush dev %i ExecStop=/bin/ip link set dev %i down ExecStop=-/bin/bash -c "test -f /etc/conf.d/postdown@%i.sh&&/bin/bash -c /etc/conf.d/postdown@%i.sh" [Install] WantedBy=multi-user.target and the /etc/conf.d/network@eno1 is address=192.168.0.1 netmask=24 broadcast=192.168.0.255 So, before I run this, I don't think the card has any ip address, does it? -- Your life is like a penny. You're going to lose it. The question is: How do you spend it? John Covici wb2una cov...@ccs.covici.com
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On Thu, Feb 16, 2023 at 6:50 AM John Covici wrote: > > The sending computer has two nics, eno1 for the internal network and > eno2 is on the internet. So, my netconsole stanza said > netconsole=@192.168.0.1/eno1,@192.168.0.2 Is CONFIG_NETCONSOLE enabled for your kernel? I'm not sure if the kernel will assign the names eno1/2 to interfaces - I think those might be assigned by udev, which probably won't have run before the kernel parses this instruction. You might need to use eth0/1 - and your guess is as good as mine which one corresponds to which. If it isn't one of those it might not hurt to put the target mac address in there just to be safe. I haven't needed that but maybe there are situations where ARP won't work (it would be needed if you are crossing subnets, in which case you'd need the gateway MAC). Keep in mind that this is a low-level function that doesn't use any routing/userspace/etc. It was designed to be robust in the event of a PANIC and to be able to be enabled fairly early during boot, so it can't rely on the sorts of things we just take for granted with networking. > > The box which is at 192.168.0.2 has netcat (windows version) and I > tried the following: > netcat -u -v -l 192.168.0.2 and I also tried 192.168.0.1 > which is the ip address of the linux console which I am trying to > debug. > > I also tried 0.0.0.0 which did not work either, but I think the > windows firewall was blocking, and I did fix that, but did not try the > 0.0.0.0 after that. > So I'm pretty sure that netcat requires listing the destination IP, since it has to open a socket to listen on that IP. You can optionally set a source address/port in which case it will ignore anything else, but by default it will accept packets from any source. I was definitely going to suggest making sure that a windows firewall wasn't blocking the inbound connections. That's fairly default behavior on windows. -- Rich
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On Wed, 15 Feb 2023 09:50:27 -0500, Grant Edwards wrote: > > On 2023-02-14, Rich Freeman wrote: > > > Where are you getting this from, the system log/journal? This doesn't > > seem like a clean shutdown, so if it is a kernel PANIC I wouldn't > > expect the most critical info to be in the log (since it will stop > > syncing to protect the filesystem). The details you need probably > > will be displayed on the console briefly. You can also enable a > > network console, which will send the dmesg output continuously over > > UDP to another device. This won't be interrupted by a PANIC unless > > there is some issue with the hardware or networking stack. > > If you've got a serial port[1], you could also set up serial > logging. Though using serial ports have become a bit of a lost art, > the serial console code in the kernel is pretty carefully designed to > be the last man standing when things start to die. It's possible > (though I wouldn't say probable) that a serial console will be able to > show you stuff closer to the event horizon than a network console can. > > Anyway, since still I'm in the serial port business (yes, there are > still plenty of people using serial ports in industrial settings) I > had to mention it... > > [1] For this purpose you want a plain old UART on the motherboard type > seial port. You'd be surprised how many motherboards still have > them. Even though they're never brought out to a DB9 connector on > the back panel, there's often an 8-pin header on the edge of the > board somewhere, so you'd need one of these: > > > https://www.amazon.com/C2G-27550-Adapter-Bracket-Motherboards/dp/B0002J27R8/ > > Still having problems with the netconsole -- I am determined to get this working,so let me explain a bit more. The sending computer has two nics, eno1 for the internal network and eno2 is on the internet. So, my netconsole stanza said netconsole=@192.168.0.1/eno1,@192.168.0.2 The box which is at 192.168.0.2 has netcat (windows version) and I tried the following: netcat -u -v -l 192.168.0.2 and I also tried 192.168.0.1 which is the ip address of the linux console which I am trying to debug. I also tried 0.0.0.0 which did not work either, but I think the windows firewall was blocking, and I did fix that, but did not try the 0.0.0.0 after that. So, what am I doing wrong here? -- Your life is like a penny. You're going to lose it. The question is: How do you spend it? John Covici wb2una cov...@ccs.covici.com
[gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On 2023-02-15, Grant Edwards wrote: > [1] For this purpose you want a plain old UART on the motherboard type > seial port. You'd be surprised how many motherboards still have > them. Even though they're never brought out to a DB9 connector on > the back panel, there's often an 8-pin header on the edge of the > board somewhere, so you'd need one of these: Oops, it's a 10pin (2x5) header not an 8-pin header, as I'm sure you'd have figured out.
Re: [gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On Wed, 15 Feb 2023 09:50:27 -0500, Grant Edwards wrote: > > On 2023-02-14, Rich Freeman wrote: > > > Where are you getting this from, the system log/journal? This doesn't > > seem like a clean shutdown, so if it is a kernel PANIC I wouldn't > > expect the most critical info to be in the log (since it will stop > > syncing to protect the filesystem). The details you need probably > > will be displayed on the console briefly. You can also enable a > > network console, which will send the dmesg output continuously over > > UDP to another device. This won't be interrupted by a PANIC unless > > there is some issue with the hardware or networking stack. > > If you've got a serial port[1], you could also set up serial > logging. Though using serial ports have become a bit of a lost art, > the serial console code in the kernel is pretty carefully designed to > be the last man standing when things start to die. It's possible > (though I wouldn't say probable) that a serial console will be able to > show you stuff closer to the event horizon than a network console can. > > Anyway, since still I'm in the serial port business (yes, there are > still plenty of people using serial ports in industrial settings) I > had to mention it... > > [1] For this purpose you want a plain old UART on the motherboard type > seial port. You'd be surprised how many motherboards still have > them. Even though they're never brought out to a DB9 connector on > the back panel, there's often an 8-pin header on the edge of the > board somewhere, so you'd need one of these: > > > https://www.amazon.com/C2G-27550-Adapter-Bracket-Motherboards/dp/B0002J27R8/ 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. Thanks for the hint. -- Your life is like a penny. You're going to lose it. The question is: How do you spend it? John Covici wb2una cov...@ccs.covici.com
[gentoo-user] Re: my 5.15.93 kernel keeps rebooting
On 2023-02-14, Rich Freeman wrote: > Where are you getting this from, the system log/journal? This doesn't > seem like a clean shutdown, so if it is a kernel PANIC I wouldn't > expect the most critical info to be in the log (since it will stop > syncing to protect the filesystem). The details you need probably > will be displayed on the console briefly. You can also enable a > network console, which will send the dmesg output continuously over > UDP to another device. This won't be interrupted by a PANIC unless > there is some issue with the hardware or networking stack. If you've got a serial port[1], you could also set up serial logging. Though using serial ports have become a bit of a lost art, the serial console code in the kernel is pretty carefully designed to be the last man standing when things start to die. It's possible (though I wouldn't say probable) that a serial console will be able to show you stuff closer to the event horizon than a network console can. Anyway, since still I'm in the serial port business (yes, there are still plenty of people using serial ports in industrial settings) I had to mention it... [1] For this purpose you want a plain old UART on the motherboard type seial port. You'd be surprised how many motherboards still have them. Even though they're never brought out to a DB9 connector on the back panel, there's often an 8-pin header on the edge of the board somewhere, so you'd need one of these: https://www.amazon.com/C2G-27550-Adapter-Bracket-Motherboards/dp/B0002J27R8/ -- Grant