Public bug reported: My main server has been running into hard lockups about once a week ever since I switched to the 4.15 Ubuntu 18.04 kernel.
When this happens, nothing is printed to the console, it's effectively stuck showing a login prompt. The system is running with panic=1 on the cmdline but isn't rebooting so the kernel isn't even processing this as a kernel panic. As this felt like a potential hardware issue, I had my hosting provider give me a completely different system, different motherboard, different CPU, different RAM and different storage, I installed that system on 18.04 and moved my data over, a week later, I hit the issue again. We've since also had a LXD user reporting similar symptoms here also on varying hardware: https://github.com/lxc/lxd/issues/5197 My system doesn't have a lot of memory pressure with about 50% of free memory: root@vorash:~# free -m total used free shared buff/cache available Mem: 31819 17574 402 513 13842 13292 Swap: 15909 2687 13222 I will now try to increase console logging as much as possible on the system in the hopes that next time it hangs we can get a better idea of what happened but I'm not too hopeful given the complete silence on the console when this occurs. System is currently on: Linux vorash 4.15.0-36-generic #39-Ubuntu SMP Mon Sep 24 16:19:09 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux But I've seen this since the GA kernel on 4.15 so it's not a recent regression. ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1799497 Title: 4.15 kernel hard lockup about once a week Status in linux package in Ubuntu: New Bug description: My main server has been running into hard lockups about once a week ever since I switched to the 4.15 Ubuntu 18.04 kernel. When this happens, nothing is printed to the console, it's effectively stuck showing a login prompt. The system is running with panic=1 on the cmdline but isn't rebooting so the kernel isn't even processing this as a kernel panic. As this felt like a potential hardware issue, I had my hosting provider give me a completely different system, different motherboard, different CPU, different RAM and different storage, I installed that system on 18.04 and moved my data over, a week later, I hit the issue again. We've since also had a LXD user reporting similar symptoms here also on varying hardware: https://github.com/lxc/lxd/issues/5197 My system doesn't have a lot of memory pressure with about 50% of free memory: root@vorash:~# free -m total used free shared buff/cache available Mem: 31819 17574 402 513 13842 13292 Swap: 15909 2687 13222 I will now try to increase console logging as much as possible on the system in the hopes that next time it hangs we can get a better idea of what happened but I'm not too hopeful given the complete silence on the console when this occurs. System is currently on: Linux vorash 4.15.0-36-generic #39-Ubuntu SMP Mon Sep 24 16:19:09 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux But I've seen this since the GA kernel on 4.15 so it's not a recent regression. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1799497/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
