Darac Marjal <mailinglist@darac.org.uk> writes:
> On Tue, Feb 24, 2015 at 11:23:08AM +0000, Sharon Kimble wrote:
>> I have just bought a new computer,a Lenovo 050 desktop. Its working
>> reasonably okay except for the occasional crashes. For instance, I've
>> had it a fortnight now and its longest uptime has been just over 3
>> days, even though its on all the time!
>>
>> It has crashed when I've been using it, and its crashed overnight
>> whilst I've been asleep! There does not seem to be any pattern to
>> it, or any noticeable trigger.
>>
>> When it crashes, the screen freezes, and both the usb keyboard and
>> mouse freeze, and can not be used.
>>
>> In its most recent crash, it shows this in logwatch the following day
>>
>> --8<---------------cut here---------------start------------->8---
>> --------------------- Kernel Begin ------------------------
>>
>>
>> WARNING: Segmentation Faults in these executables
>> Watchdog : 2 Time(s)
>
> You appear to be running a watchdog process, which is crashing. A
> hardware watchdog will, generally speaking, work as follows: at boot, it
> will do nothing, but when an application writes a specific command to
> it, it will start a timer (30 seconds, 60 seconds, etc. Often
> configurable). When the timer expires, the watchdog will cause the
> computer to reset. However, when the application writes the command to
> the watchdog again, the timer is reset back to the start. So, as long as
> the watchdog process is alive, it is able to keep resetting the clock
> and the machine works fine. But if the processes stops (because the
> machine has hung, or the system is too busy), then the timer will
> expire, the machine will reboot and you can get back to work.
After looking more closely I don't have "watchdog" installed! There
is no conf file for it, there is no executable for it, there is no
man page for it, and apt-cache-policy shows
--8<---------------cut here---------------start------------->8---
acp watchdog
watchdog:
Installed: (none)
Candidate: 5.14-3
Version table:
5.14-3 0
500 http://mirror.bytemark.co.uk/debian/ jessie/main i386 Packages
--8<---------------cut here---------------end--------------->8---
which is why the machine freezes when its called, and also why it
segfaults! Logically then, if the machine freezes without it, I need
to install it, which I've just done. And so I'll just wait and see
what happens now.
Thanks all
Sharon.
>
> In your case, though, it looks like the watchdog process is dying
> because of a Segmentation Fault (see the full logs or a core file for
> full details). At that point, even though the rest of the system is
> running fine, no-one is resetting the watchdog clock.
>
>>
>> WARNING: Kernel Errors Present
>> INFO: recovery required on readonly filesyste ...: 1 Time(s)
>> mce: [Hardware Error]: Machine check ...: 4 Time(s)
>
> You are seeing Machine Check Exceptions. These may or may not be a
> problem. This is usually the CPU saying "I ran into an error". This
> could be the cause of your Segmentation Fault, for example - the
> watchdog executes an invalid command, the processor complains and the
> watchdog receives a SegFault as a result. I suspect the difference
> between this and a SIGILL (Illegal Instruction) is that, while the
> instruction is technically valid, the data or the state of the processor
> or something like that is resulting in an error. It IS possible that the
> code is perfectly correct, but the processor is calculating the wrong
> answer (because of a hardware error).
>
>>
>> ---------------------- Kernel End -------------------------
>>
>> --------------------- Connections (secure-log) Begin ------------------------
>>
>> New Users:
>> glances (123)
>>
>> New Groups:
>> glances (134)
>>
>>
>> Changed password expiry for users:
>> glances : 1 Time(s)
>>
>> **Unmatched Entries**
>> lightdm: pam_ck_connector(lightdm:session): nox11 mode, ignoring PAM_TTY :0: 1 Time(s)
>> systemd-logind: New seat seat0.: 1 Time(s)
>> systemd-logind: Watching system buttons on /dev/input/event3 (Power Button): 1 Time(s)
>> systemd-logind: Watching system buttons on /dev/input/event4 (Sleep Button): 1 Time(s)
>> systemd-logind: Watching system buttons on /dev/input/event5 (Power Button): 1 Time(s)
>> systemd-logind: Watching system buttons on /dev/input/event7 (Video Bus): 1 Time(s)
>> usermod: change user 'glances' password: 1 Time(s)
>
> You've included this information. Did you not create the user "glances"
> yourself?
>
>>
>> ---------------------- Connections (secure-log) End -------------------------
>> --8<---------------cut here---------------end--------------->8---
>>
>> What should I -
>> a) - install, to get a better idea of why its crashing?
>> b) - do to stop/get round the crashing please?
>>
>> Thanks
>> Sharon.
>> --
>> A taste of linux = http://www.sharons.org.uk
>> my git repo = https://bitbucket.org/boudiccas/dots
>> TGmeds = http://www.tgmeds.org.uk
>> Debian testing, fluxbox 1.3.6, emacs 24.4.1.0
--
A taste of linux = http://www.sharons.org.uk
my git repo = https://bitbucket.org/boudiccas/dots
TGmeds = http://www.tgmeds.org.uk
Debian testing, fluxbox 1.3.6, emacs 24.4.1.0
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