Date: Wed, 20 Jun 2018 15:37:23 +0000 From: Holger Kipp <Holger.Kipp@alogis.com> To: Miroslav Lachman <000.fbsd@quip.cz> Cc: "freebsd-stable@freebsd.org" <freebsd-stable@freebsd.org> Subject: Re: iostat busy value calculation Message-ID: <5765F5AE-131A-4F2F-8C46-9E362611CDA1@alogis.com> In-Reply-To: <98c4156c-d2f0-f0c6-b859-9cea8ec29a42@quip.cz> References: <98c4156c-d2f0-f0c6-b859-9cea8ec29a42@quip.cz>
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Dear Miroslav,
looking at the manpage for iostat I see:
%b % of time the device had one or more outstanding transac=
tions
tsvc_t/i
total duration of transactions per time period, in secon=
ds
sb/i total time the device had one or more outstanding transa=
c-
tions per time period, in seconds
So calculating the percentage using sb/i should be fairly easy.
Best regards,
Holger
Am 20.06.2018 um 16:55 schrieb Miroslav Lachman <000.fbsd@quip.cz<mailto:00=
0.fbsd@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 f=
irst 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 co=
lumn 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 "bus=
y" 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?
Miroslav Lachman
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