Holger Kipp wrote on 2018/06/20 17:37:> Dear Miroslav,
>
> looking at the manpage for iostat I see:
>
> %b % of time the device had one or more outstanding
transactions
> tsvc_t/i
> total duration of transactions per time period, in
seconds
> sb/i total time the device had one or more outstanding
transac-
> tions per time period, in seconds
>
> So calculating the percentage using sb/i should be fairly easy.
If I understand it correctly, then it cannot be calculated from numbers
between two independent runs of "iostat -I -x" because it gives me
sb/i
average from the boot time, so the calculated %b will be overall average
instead of average between two runs after 60 seconds.
The only possible way to calculated is to run "iostat -I -x -c 2 -w
60"
where the sb/i value of the second line will be average of these last 60
seconds. But it also means monitoring probe will wait 60 seconds to get
this value (each time) so it is the same problem as I described in my
original post with "iostat -x".
Miroslav Lachman
> Am 20.06.2018 um 16:55 schrieb Miroslav Lachman <000.fbsd at
quip.cz<mailto:000.fbsd at quip.cz>>:
>
> I would like to know how the value of disk "busy" is calculated?
>
> I want to use values from iostat in the monitoring (zabbix).
> iostat shows averages by default and the last column is "busy %",
but the first output contains averages from the system boot til now.
>
> # iostat -x -t da
> extended device statistics
> device r/s w/s kr/s kw/s qlen svc_t %b
> ada0 2.5 13.8 49.0 287.9 0 45.7 2
> ada1 2.6 13.8 51.7 287.9 0 39.6 2
>
> I don't want to use "iostat -x -t da -w 20" to get averages
of the last 20 seconds because it means monitoring needs to wait 20 seconds on
each run.
>
> I can use absolute values from iostat. This output is without any delay and
the monitoring SW can calculate averages between two runs. But the last column
is no busy %, it is sb/i.
>
> # iostat -I -x -t da
> extended device statistics
> device r/i w/i kr/i kw/i qlen tsvc_t/i
sb/i
> ada0 7403218.0 40825749.0 144647824.0 849655694.0 0 2204904.2
73121.8
> ada1 7537423.0 40825749.0 152643874.5 849655694.0 0 1914301.0
69996.5
>
> So the question is - If I want to plot "busy %" in the graph -
how the "busy" value in the first example is calculated?
> Is it possible to calculate it from the numbers that I have from
"iostat -I -x" and the know time interval between two runs?