Ubuntu 9.10 Karmic Koala: Temperature above threshold, cpu clock throttled

I recently upgraded my Ubuntu install to the latest Karmic Koala, and to be honest I’ve not been totally impressed.   A range of little bugs that had been fixed before seem to have reappeared – just little things such as problems with icons in Gnome panel, nothing I couldn’t live with.

However, yesterday I got a message saying that there was less than 2GB left on my hard drive.   The last time I checked I had over 20GB free, so where did it all go?   After a bit of investigating I found two giant 10GB kernel log files /var/log/kern.log.

It seemed that the computer was constantly logging the same messages:

CPU0: Temperature above threshold, cpu clock throttled (total events = 208[ 8973.550089] CPU0: Temperature/speed normal

CPU0: Temperat cpu clock throttled (total events = 2080190)

I had a look on Google and it turns out that it is a bug with the new Karmic Koala update:


So far there’s no patch for it, so the best solution I came up with was just to turn off the logging.

Step 1:
Look in /etc/rsyslog.conf and it will either have the configuration for system logging, or in the case of my machine it points to include all files in /etc/rsyslog.d/   In my case there was only one file in here so it made things simpler.

Step 2:
Open the configuration file in an editor and find the line which specifies kernel logging and comment it, something like:

#kern.*                         -/var/log/kern.log

Step 3:
Now restart the system log daemon:   sudo restart rsyslog

It is the logging which hogs the processor so by turning it off the problem is at least not noticeable.

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7 Responses to Ubuntu 9.10 Karmic Koala: Temperature above threshold, cpu clock throttled

  1. perspectoff says:

    You have to comment out the lines for syslog, too. The rsyslog daemon logs to both…

    You ought to turn off ONDEMAND CPU frequency scaling (throttling) with rcconf, too.

  2. Nick says:

    You’re quite right, sorry, I forgot to mention that. You should be able to tell if it worked because once you restart the daemon you should see in the kern.log file this:

    kernel: Kernel logging (proc) stopped.

    I’ll give turning off frequency scaling a try – thanks for that!

  3. leo says:

    hi,i get a new solution from https://bugs.launchpad.net/ubuntu/karmic/+source/rsyslog/+bug/453444, you can try it:

    I wrote a file /etc/rsyslog.d/10-temperature.conf with the following content:

    :msg,contains,”Temperature/speed normal” ~
    :msg,contains,”Temperature above threshold” ~

    All messages containing “Temperature/speed normal” and “Temperature above threshold” are discarded.
    I restarted rsyslog and it looks like the problem is solved.

    I hope this will help until the problem will be fixed in the kernel.

  4. Nick says:

    Thanks for that – it’s a much cleaner solution!

  5. coolfan says:

    Just an FYI for others who might get such errors:
    Note that one logical possibility is that the CPU is actually getting heated up beyond what it should – it could be malfunction in the CPU fan, heatsink, CPU sensors, or of course some problem with numeric settings of temperature/throttling.
    So once in a while it is good to look inside the box to see if there is any lose parts, broken parts, problem with the CPU fan, too much dust, CPU cooling paste ha dried up or some such issue.

  6. kk says:


    Which are found in /var/log

    1 . kern.log (already mentioned at top )(on my system it was 346.6 MB )

    2. sys.log( its contents are exact replica of kern.log also 346.6 MB)

    3 . messages( it is not a .log file but yet reported as 145.6 MB )

    And remember all these are after only 12 hrs of uptime ,and i am on a old intel 845gl P4 760 MB Ram setup, the cpu was always 100% ,and in a few previous days life was hell, system would hang up anytime , and i was clueless despite numerous tries . I was sure it was not a fan issue as i have cleaned the cpu fan recently

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