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    Help: Clean shutdown of Host, now no network or VMs are detected

    Scheduled Pinned Locked Moved Solved Compute
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    • C Offline
      CodeMercenary @guiltykeyboard
      last edited by

      @guiltykeyboard Restarting the toolstack on the pool master did not fix it so I went ahead and did the emergency network reset on the host having the issue. It came up normally after the reboot. The emergency reset was super easy, Thank you for helping me with this. Still learning XCP-ng and trying to understand what's happening before trying things to fix it, so in the future I'll know more and hopefully be able to help other people.

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      • G Offline
        guiltykeyboard @CodeMercenary
        last edited by

        @CodeMercenary Glad it worked out for you.

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        • C Offline
          CodeMercenary
          last edited by

          Another bit of strangeness. I just noticed that some older backup disaster recovery VMs were booted up on my pool master host. I looked at the stats and they all booted 4 hours ago, right around when I tried restarting the toolstack on the pool master. All of them were set to auto-start, an odd setting I think for disaster recovery VMs unless there is supposed to be something in place to stop them from auto-starting. Easy enough to shut down but kinda strange that they booted. Surely disaster recovery VMs aren't supposed to power up on restart, right?

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          • olivierlambertO Offline
            olivierlambert Vates 🪐 Co-Founder CEO
            last edited by

            They shouldn't yes. Were you using DR or CR?

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            • olivierlambertO olivierlambert has marked this topic as solved on
            • C Offline
              CodeMercenary @olivierlambert
              last edited by

              @olivierlambert It was DR. I was testing DR a while ago and after running it once I disabled the backup job so these backups have just been sitting on the server. I don't think I've rebooted that server since running that backup.

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              • nick.lloydN nick.lloyd referenced this topic on
              • C Offline
                CodeMercenary
                last edited by

                Just want to document that this happened again, on the same host.

                My XO (from source) that manages my backups, ran the backups last night. I know it was active up until at least around 5:30am but by the time I got into the office it was inaccessible by browser, ssh and ping. Other XO instances showed that it was running but the Console tab didn't give me access to its console.

                A few hours later I found that other VMs on that same host had become inaccessible in the same fashion and also had no console showing in XO.

                An hour or two later I found that XO showed the host as being missing from the pool, which it had not been earlier in the day. When I checked the physical console for that host, I found it had red text "<hostname> login: root (automatic login)" and did not respond to the keyboard other than putting more red text on screen of whatever I typed. I hit ctrl-alt-del and it didn't seem to do anything so I typed random things, then XCP-ng started rebooting. I'm guessing it was 60 to 120 seconds after my first ctrl-alt-delete.

                When it came back up it could not find the pool master and said it had no network interfaces. I was able to solve it by doing another emergency network reset.

                Would be nice if this wouldn't happen, makes me super nervous about stability. Thankful that the two times this has happened, it was on my least mission critical server. However, it's the server that handles backups so it's still stressful to have it go down. Also makes me wonder if there might be something wrong with that server's hardware.

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                • olivierlambertO Offline
                  olivierlambert Vates 🪐 Co-Founder CEO
                  last edited by

                  You need to check the logs because obviously it's not normal. Check if you have a /var/crash folder with some stuff in it. Otherwise, the usual logs to check (on both xen and dom0 side).

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                  • C Offline
                    CodeMercenary @olivierlambert
                    last edited by

                    @olivierlambert I do have a /var/crash folder but it has nothing it in except a file from a year ago named .sacrificial-space-for-logs.

                    The Xen logs are verbose. Any suggestions of text to grep to find what I'm looking for? Other than the obvious error I should search for.

                    Currently looking in xensource.log.* for error lines to see if I can figure anything out.

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                    • olivierlambertO Offline
                      olivierlambert Vates 🪐 Co-Founder CEO
                      last edited by

                      kernel log and Xen log, check for anything around the time of the issue

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                      • C Offline
                        CodeMercenary @olivierlambert
                        last edited by

                        @olivierlambert Having trouble finding the reboot in the log files because I don't know what to look for. I have nearly 1GB of log files from that day and unfortunately, I don't recall when the reboot happened. Is there something I can grep for in the log that would indicate the reboot and I can backtrack from there?

                        Tried feeding the GB of log files to Phi4 in my Ollama server but so far it has not been any help finding anything either. Well, it found how to make my office a lot louder by running the server fans at full speed for a few minutes but that wasn't helpful.

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                        • C Offline
                          CodeMercenary @CodeMercenary
                          last edited by

                          Looking through the kern.log files I found stuff I thought might be interesting but as I scroll, I see it happening a lot so I then wonder if it's normal. I see sets of three events:
                          Out of memory: Kill process ###
                          Killed process ###
                          oom_reaper: reaped process ###

                          I wonder if it was starving for memory and having to kill off processes to survive then eventually died. I see these 90+ times in one log file and over 200 times in another. Don't know if this is just normal activity or indication of a problem.

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                          • K Offline
                            kassebasse @CodeMercenary
                            last edited by kassebasse

                            @CodeMercenary I had a simillar issue to you, check the time and the date on the host.

                            If this might be any help to you: https://xcp-ng.org/forum/topic/10687/after-an-update-the-nic-s-has-disappeared-but-still-works-somehow/10?_=1743764792775

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