Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

It is happens sometimes, im just working and suddenly machine starts lagging. Then it can totaly stops (Nothing works, mouse, keyboard etc.), or sometimes not.

Jun  5 16:04:12 c0rp kernel: [ 2636.897221] CPU1: Package power limit normal
Jun  5 16:04:12 c0rp kernel: [ 2636.897222] CPU3: Package power limit normal
Jun  5 16:04:12 c0rp kernel: [ 2636.897224] CPU2: Package power limit normal
Jun  5 16:04:12 c0rp kernel: [ 2636.897225] CPU0: Package power limit normal
Jun  5 16:05:01 c0rp CRON[6655]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Jun  5 16:10:26 c0rp kernel: imklog 5.8.6, log source = /proc/kmsg started.
Jun  5 16:10:26 c0rp rsyslogd: [origin software="rsyslogd" swVersion="5.8.6" x-pid="1267" x-info=""] start

This is whats inside syslog quite before hard reset

(command -v debian-sa1 > /dev/null && debian-sa1 1 1) may be this is my problem?

uname -a

Linux c0rp 3.8.6-030806-generic #201304051406 SMP Fri Apr 5 18:07:42 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

Also just before lagging iowait are up

My laptop: Asus Zenbook UX32DV, Ubuntu 12.10 Sorry for my poor english

Edit 1: According to the jnv answer I remove sysstat package. The problem still exists, but now my computer doesn't stops totally. iowait very high, machine lagging and sometimes stops for 20-30 sec. I'm still trying to find a culprit. My hdd is healthy (Smart Data and test utility said). sometimes in iotop output there is kswapd0 causing 80-90% iowait.

Edit 2: According last jnv answer. Yesterday I upgraded my 12.10 to 13.04. Today everything was normal. No iowaits, no lagging.

I explain a little bit my configuration on laptop. My / and /boot are on SSD. Also 2 2Gb swap files on SSD. Swappiness is 10. /home on hdd. zRam is installed, i have 4 zRam partitions.

Also I ordered one 8Gb RAM, and later plan to buy 256Gb SSD and change HDD. If someone intersted here is good HOWTO article. Its in german but google can help.

share|improve this question
up vote 2 down vote accepted

debian-sa1 and the cron job seem to come from the sysstat package; try uninstalling the package to confirm whether it's a cause of lagging:

sudo apt-get remove sysstat

If it won't help, you can at least eliminate one possible cause.

Edit: According to your information, sysstat isn't a problem. However since you have pointed out kswapd for high I/O activity, the problem is probably caused by swapping – which usually leads to notable performance degradation (however it should not kill your system). See What are kswapd0, kworker/num:num, ksoftirqd/num? for information about kernel threads, including kswapd.

There are few ways to address issues with swap:

  • Reduce swappiness – value about 1 to 10 could be useful
  • Try using zRam which compresses RAM; it may or may not help depending on your usecase and hardware
  • Buy more RAM :)

Also, if I am not mistaken, your laptop contains a smaller SSD which Windows OS uses for caching; I am not sure whether it can be utilised by Linux in the same way, however if you don't dualboot, you could use the SSD for the root system or some of its parts (with /home on a primary HDD) – see i.e. How to dualboot Ubuntu on Asus Zenbook UX32VD? and What's a good partition method to combine an SSD boot drive with a 1TB data drive? and ArchWiki on tips how to utilise SSD. Anyway, as pointed elsewhere, it's not really a good idea to move swap to SSD due to its limited read/write cycles.

share|improve this answer
thanks! I will try, test, and then write results – c0rp Jun 7 '13 at 5:58
Thanks for answering! Your previous advice has helped partially, sysstat package is not first culprit. – c0rp Jun 10 '13 at 5:12
Thanks, according to your updated details it seems the main culprit could be swap. I have updated my answer with more information. – jnv Jun 10 '13 at 12:13
Thanks for advices. Today i ordered RAM. – c0rp Jun 11 '13 at 16:35

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.