Re: Null performance during a test

On Fri, Jul 20 2007, Erwan Velu wrote:
> Hey Jens,
>
> Here come the bw line from a disk_profile_zone test:
> bw (KiB/s) : min= 0, max=66715, per=96.11%, avg=62230.60,
> stdev=12736.12
>
> I was very surprised to see 0 as min. I looked into the bw file and found
> some lines like :
> 2193590, 0, 0
>
> I tried to find the number of lines and found 181 null measures.
>
> [root_at_max1 ~]# grep ", 0, 0" client1_bw.log | wc -l
> 181
> [root_at_max1 ~]#
>
> My job have 4569 entries in the bw.log file meaning that near 4% of my
> requests reports a null size.
>
> Do you have any idea why I have such results ? Looks like an IO at 0K/sec
> is nearly impossible for a huge set of sequential requests of 64KB blocks.
>
> This null results turn my average & stdev wrong :/

Interesting, that definitely sounds like a bug as well. Will
investigate.

-- 
Jens Axboe