Comment 1 for bug 307961

On Sun, 14 Dec 2008, Noel J. Bergman wrote:

> Public bug reported:
>
> Consider the following:
>
> ~$ dstat --disk -Dtotal,sdb1,sdc1
> -dsk/total----dsk/sdb1----dsk/sdc1-
> read writ: read writ: read writ
> 507k 461k: 46k 0 : 5.4B 43k
> 43M 53M: 21M 0 : 0 26M
> 38M 31M: 19M 0 : 0 15M
> 42M 35M: 21M 0 : 0 17M
>
> and also:
>
> $ dstat --disk -Dtotal,sdb,sdc
> -dsk/total----dsk/sdb-----dsk/sdc--
> read writ: read writ: read writ
> 510k 464k: 47k 0 : 9.6B 45k
> 53M 55M: 27M 0 : 0 27M
> 35M 41M: 18M 0 : 0 20M
> 103M 94M: 52M 0 : 0 46M
>
> Notice that the disk/total for read and write is double that of the actual disk. Based upon looking at (trimmed):
> ~$ dstat -f
> --dsk/sda-----dsk/sda1---dsk/sda10----dsk/sda2----dsk/sda5----dsk/sda6----dsk/sda7----dsk/sda8----dsk/sda9----dsk/sdb-----dsk/sdb1----dsk/sdc-----dsk/sdc1-
> read writ: read writ: read writ: read writ: read writ: read writ: read writ: read writ: read writ: read writ: read writ: read writ: read writ
> 209k 189k: 3.7B 0 : 157k 129k: 0 0 : 1.2B 0 : 1.1B 0 : 1B 0 : 51k 59k: 90B 766B: 270k 0 : 270k 0 : 9.5B 267k: 5.3B 267k
> 884k 220k: 0 0 : 0 8192B: 0 0 : 0 0 : 0 0 : 0 0 : 884k 212k: 0 0 : 24M 0 : 24M 0 : 0 14M: 0 14M
> 0 188k: 0 0 : 0 0 : 0 0 : 0 0 : 0 0 : 0 0 : 0 188k: 0 0 : 25M 0 : 25M 0 : 0 29M: 0 29M
>
> I suspect that dstat is processing both sd<x> and sd<x><y>, e.g., sda &
> sda1, resulting in the doubled values.
>
> ** Affects: dstat (Ubuntu)
> Importance: Undecided
> Status: New

I cannot help if I don't know what dstat version and what kernel. On my
system I do not see that behaviour, but it is not impossible that this
behaviour exists with older dstat versions and/or older or newer kernel
versions.

This bugreport is useless if it does not specify this minimum information,
sorry.

--
-- dag wieers, <email address hidden>, http://dag.wieers.com/ --
[Any errors in spelling, tact or fact are transmission errors]