Hi.. I had to remove zram config from my production servers long ago. ...
since then I don't have the issue.  I was using LXD containers a lot on the
hosts with different kind of usage,, But I don't have any other setup at
the moment

On Fri, Jan 10, 2020 at 12:11 AM Colin Ian King <email address hidden>
wrote:

> Can reproduce this with stress-ng exercising high memory pressure scenario
> using:
> stress-ng --brk 0 -v --aiol 0
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1799497
>
> Title:
>   4.15 kernel hard lockup about once a week
>
> Status in linux package in Ubuntu:
>   Incomplete
> Status in zram-config package in Ubuntu:
>   Incomplete
> Status in linux source package in Bionic:
>   Confirmed
> Status in zram-config source package in Bionic:
>   Confirmed
>
> 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.
>   ---
>   ProblemType: Bug
>   AlsaDevices:
>    total 0
>    crw-rw---- 1 root audio 116,  1 Oct 23 16:12 seq
>    crw-rw---- 1 root audio 116, 33 Oct 23 16:12 timer
>   AplayDevices: Error: [Errno 2] No such file or directory: 'aplay':
> 'aplay'
>   ApportVersion: 2.20.9-0ubuntu7.4
>   Architecture: amd64
>   ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord':
> 'arecord'
>   AudioDevicesInUse:
>    Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed
> with exit code 1: Cannot stat file /proc/22822/fd/10: Permission denied
>    Cannot stat file /proc/22831/fd/10: Permission denied
>   DistroRelease: Ubuntu 18.04
>   HibernationDevice:
>    RESUME=none
>    CRYPTSETUP=n
>   IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig':
> 'iwconfig'
>   Lsusb:
>    Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
>    Bus 001 Device 002: ID 046b:ff10 American Megatrends, Inc. Virtual
> Keyboard and Mouse
>    Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
>   MachineType: Intel Corporation S1200SP
>   NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
>   Package: linux (not installed)
>   PciMultimedia:
>
>   ProcEnviron:
>    TERM=xterm
>    PATH=(custom, no user)
>    XDG_RUNTIME_DIR=<set>
>    LANG=en_US.UTF-8
>    SHELL=/bin/bash
>   ProcFB: 0 mgadrmfb
>   ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-38-generic
> root=UUID=575c878a-0be6-4806-9c83-28f67aedea65 ro biosdevname=0
> net.ifnames=0 panic=1 verbose console=tty0 console=ttyS0,115200n8
>   ProcVersionSignature: Ubuntu 4.15.0-38.41-generic 4.15.18
>   RelatedPackageVersions:
>    linux-restricted-modules-4.15.0-38-generic N/A
>    linux-backports-modules-4.15.0-38-generic  N/A
>    linux-firmware                             1.173.1
>   RfKill: Error: [Errno 2] No such file or directory: 'rfkill': 'rfkill'
>   Tags:  bionic
>   Uname: Linux 4.15.0-38-generic x86_64
>   UnreportableReason: This report is about a package that is not installed.
>   UpgradeStatus: No upgrade log present (probably fresh install)
>   UserGroups:
>
>   _MarkForUpload: False
>   dmi.bios.date: 01/25/2018
>   dmi.bios.vendor: Intel Corporation
>   dmi.bios.version: S1200SP.86B.03.01.1029.012520180838
>   dmi.board.asset.tag: Base Board Asset Tag
>   dmi.board.name: S1200SP
>   dmi.board.vendor: Intel Corporation
>   dmi.board.version: H57532-271
>   dmi.chassis.asset.tag: ....................
>   dmi.chassis.type: 23
>   dmi.chassis.vendor: ...............................
>   dmi.chassis.version: ..................
>   dmi.modalias:
> dmi:bvnIntelCorporation:bvrS1200SP.86B.03.01.1029.012520180838:bd01/25/2018:svnIntelCorporation:pnS1200SP:pvr....................:rvnIntelCorporation:rnS1200SP:rvrH57532-271:cvn...............................:ct23:cvr..................:
>   dmi.product.family: Family
>   dmi.product.name: S1200SP
>   dmi.product.version: ....................
>   dmi.sys.vendor: Intel Corporation
>
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>