This is a text-only version of the following page on https://raymii.org: --- Title : atop is broken on Ubuntu 16.04 (version 1.26): trap divide error Author : Remy van Elst Date : 18-09-2017 URL : https://raymii.org/s/articles/atop_is_broken_on_Ubuntu_16.04.html Format : Markdown/HTML --- Recently a few of my Ubuntu 16.04 machines had issues and I was troubleshooting them, noticing `atop` logs missing. atop is a very handy tool which can be setup to record system state every X minutes, and we set it up to run every 5 minutes. You can then at a later moment see what the server was doing, even sorting by disk, memory, cpu or network usage.

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![atop][2] Atop logs in `/var/log/atop` by date: root@server:~# ls -la /var/log/atop/ total 29916 drwxr-xr-x 2 root root 4096 Sep 18 00:00 . drwxrwxr-x 10 root syslog 4096 Sep 18 06:25 .. -rw-r--r-- 1 root root 3051661 Aug 22 00:00 atop_20170821 -rw-r--r-- 1 root root 1553161 Aug 25 00:00 atop_20170824 -rw-r--r-- 1 root root 1593178 Aug 26 00:00 atop_20170825 Using the commandline: atop -r /var/log/atop/atop_20170821 # -b time_to_start will open up atop with that log. Using `t` and `T` you can go back and forward in time. ### The issue Checking the system log this message showed up on the dates that the log was missing: Sep 18 00:00:01 server kernel: [82125.706464] traps: atop[517] trap divide error ip:4073c2 sp:7ffebe903810 error:0 in atop[400000+26000] There is a [debian bug report][3] where they state this bug is solved in the 2.x release (debian experimental). Ubuntu 16.04 sadly still ships 1.x, and due to policy will never update to 2.x. The bug is solved in December 2016, but the [ubuntu changelog][4] still shows that the last update was in January 2016: atop (2.2.6-4) unstable; urgency=medium * remove versioned dependency on initscripts. See also #852314. Thanks to Stephen Kitt (Closes: 852239) -- Marc Haber Wed, 25 Jan 2017 20:45:37 +0100 You can check the version you're running by opening `atop` and pressing `V`: Version: 1.26 - 2010/11/17 13:42:37 ### Workaround The atop version in Ubuntu 16.10 or 17.04 is the 2.x release, which you can download [on the ubuntu packages site][5]: wget http://mirrors.kernel.org/ubuntu/pool/universe/a/atop/atop_2.2.6-4_amd64.deb dpkg -i atop_2.2.6-4_amd64.deb service atop reload Afterwards you will notice that the log format is not compatible along versions: -rw-r--r-- 1 root root 1004276 Sep 18 14:54 atop_20170918 -rw-r--r-- 1 root root 18101 Sep 18 09:44 atop_20170918_pre_2_0 If you try to open a previous format logfile that will fail: root@server:~# atop -r /var/log/atop/atop_20170917 -b 23:00 raw file /var/log/atop/atop_20170917 has incompatible format (created by version 1.26 - current version 2.2) trying to activate atop-1.26.... activation of atop-1.26 failed! If you want to replay those logs, replay them on a machine with an older version of atop. Do note that using packages from another major version is not recommended. This method of installing a .deb file is also quick and dirty, a better way is to use [apt pinning][6]. [1]: https://www.digitalocean.com/?refcode=7435ae6b8212 [2]: https://raymii.org/s/inc/img/atop.png [3]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=823135 [4]: https://web.archive.org/web/20170918125630/http://changelogs.ubuntu.com/changelogs/pool/universe/a/atop/atop_2.2.6-4/changelog [5]: https://packages.ubuntu.com/zesty/amd64/atop/download [6]: https://wiki.debian.org/AptPreferences --- License: All the text on this website is free as in freedom unless stated otherwise. This means you can use it in any way you want, you can copy it, change it the way you like and republish it, as long as you release the (modified) content under the same license to give others the same freedoms you've got and place my name and a link to this site with the article as source. This site uses Google Analytics for statistics and Google Adwords for advertisements. You are tracked and Google knows everything about you. Use an adblocker like ublock-origin if you don't want it. All the code on this website is licensed under the GNU GPL v3 license unless already licensed under a license which does not allows this form of licensing or if another license is stated on that page / in that software: This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . Just to be clear, the information on this website is for meant for educational purposes and you use it at your own risk. I do not take responsibility if you screw something up. Use common sense, do not 'rm -rf /' as root for example. If you have any questions then do not hesitate to contact me. See https://raymii.org/s/static/About.html for details.