+1 for atop. Be sure to adjust the sampling interval so it suits your needs. It'll tell you what caused the spike.
Alternatively you could probably use sysdig, but I expect that'd result in a fair performance hit if your system is already struggling.
Micky
On 14 February 2018 at 08:15, Gunnar "Nick" Bluth <gunnar.bluth@xxxxxxxxxxx> wrote:
Am 06.02.2018 um 15:31 schrieb Thomas Güttler:
>
>
> Am 05.02.2018 um 14:26 schrieb Andreas Kretschmer:
>>
>>
>> Am 05.02.2018 um 14:14 schrieb Thomas Güttler:
>>> What do you suggest to get some reliable figures?
>>
>> sar is often recommended, see
>> https://blog.2ndquadrant.com/in-the-defense-of-sar/ .
>>
>> Can you exclude other reasons like vacuum / vacuum freeze?
>
> In the current case it was a problem in the hypervisor.
>
> But I want to be prepared for the next time.
>
> The tool sar looks good. This way I can generate a chart where I can see
> peaks. Nice.
>
> .... But one thing is still unclear. Imagine I see a peak in the chart.
> The peak
> was some hours ago. AFAIK sar has only the aggregated numbers.
>
> But I need to know details if I want to answer the question "Why?". The
> peak
> has gone and ps/top/iotop don't help me anymore.
>
> Any idea?
I love atop (atoptool.nl) for exactly that kind of situation. It will
save a snapshot every 10 minutes by default, which you can then simply
"scroll" back to. Helped me pinpointing nightly issues countless times.
Only really available for Linux though (in case you're on *BSD).
Best regards,
--
Gunnar "Nick" Bluth
RHCE/SCLA
Mobil +49 172 8853339
Email: gunnar.bluth@xxxxxxxxxxx
____________________________________________________________ _
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Ten years later they are choosing Windows over UNIX.
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