Re: AIO and Buffer Waits
Most bufwaits are caused by contention for the LRU queues, so increase the
LRU queues for your buffer caches to maximum first. Use the BTR calculation
and observing activity in onstat -P over time to determine if you may also
need more buffers.
Art
Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
Blog: http://informix-myview.blogspot.com/
Disclaimer: Please keep in mind that my own opinions are my own opinions and
do not reflect on my employer, Advanced DataTools, the IIUG, nor any other
organization with which I am associated either explicitly, implicitly, or by
inference. Neither do those opinions reflect those of other individuals
affiliated with any entity with which I am affiliated nor those of the
entities themselves.
On Wed, Jul 13, 2011 at 2:49 AM, Habichtsberg, Reinhard <
RHabichtsberg@arz-emmendingen.de> wrote:
> We see the following waitstates on one of our Informix 11.50FC7W3 servers.
> He is running OLTP but also Decision Support.****
>
> ** **
>
> (sum) 81125424549,00****
>
> reason aio****
>
> ** **
>
> (sum) 62105207794,00****
>
> reason buffer****
>
> ** **
>
> (sum) 61713678094,10****
>
> reason mt yield n****
>
> ** **
>
> (sum) 61561288458,60****
>
> reason mt yield****
>
> ** **
>
> (sum) 29339327941,19****
>
> reason mt ready****
>
> ** **
>
> (sum) 15649570039,20****
>
> reason running****
>
> ** **
>
> (sum) 3340893922,100****
>
> reason log i/o****
>
> ** **
>
> (sum) 1550362515,000****
>
> reason mt yield 0****
>
> ** **
>
> (sum) 1439244418,300****
>
> reason checkpoint****
>
> ** **
>
> (sum) 162272243,0000****
>
> reason lock****
>
> ** **
>
> (sum) 157356745,3000****
>
> reason mutex****
>
> ** **
>
> (sum) 21639138,60000****
>
> reason full Q****
>
> ** **
>
> What do you suggest to reduce IO and Bufferwaits. My idea is to increase
> the buffers.****
>
> ** **
>
> TIA,****
>
> Reinhard.****
>
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