RE: linux Async io

From: Hsieh, Joan <Joan.Hsieh_at_tufts.edu>
Date: Fri, 22 Mar 2013 20:38:14 +0000
Message-ID: <416FB269D9362D4AA40BE7124CA3EF9F0AAACA63_at_SSVMEXDAG01MB02.tufts.ad.tufts.edu>

I'm happy to do so. So far I have run awr reports on both servers. I'll work on it .

Thanks in advance,
Joan

-----Original Message-----
From: Frits Hoogland [mailto:frits.hoogland_at_gmail.com] Sent: Friday, March 22, 2013 4:08 PM
To: Hsieh, Joan
Cc: Mark W. Farnham; david.barbour1_at_gmail.com; oracle_l Subject: Re: linux Async io

Can you trace in both sides and run both results through orasrp? It'll give you an overview over the waits and give wait histograms.

Frits Hoogland

http://fritshoogland.wordpress.com
frits.hoogland_at_gmail.com
+31 6 53569942

(Sent from my iPhone, typo's are expected)

Op 22 mrt. 2013 om 21:01 heeft "Hsieh, Joan" <Joan.Hsieh_at_tufts.edu> het volgende geschreven:

> Thanks Mark,
>
> I'm curious the sync setting, but we are actually experiencing the performance issue, 60% of wait time is user io, db_ sequential_read is on top of it. This is a show stopper for us, and I am trying to find out the cause.
>
> Joan
>
> -----Original Message-----
> From: Mark W. Farnham [mailto:mwf_at_rsiz.com]
> Sent: Friday, March 22, 2013 2:52 PM
> To: Hsieh, Joan; 'Frits Hoogland'; david.barbour1_at_gmail.com
> Cc: 'oracle_l'
> Subject: RE: linux Async io
>
> Frits' suggestion was to sql_trace at level 8, presumably to see whether you're getting actual async i/o and the details of i/o requests, as opposed to just whether your execution plan changed. While changes to your plans may indeed be of critical interest, the thread title is about async io.
>
> mwf
>
> -----Original Message-----
> From: oracle-l-bounce_at_freelists.org
> [mailto:oracle-l-bounce_at_freelists.org]
> On Behalf Of Hsieh, Joan
> Sent: Friday, March 22, 2013 2:39 PM
> To: Frits Hoogland; david.barbour1_at_gmail.com
> Cc: oracle_l
> Subject: RE: linux Async io
>
> Thanks Frits,
> I have compared the execution plans, they both are same. I created the new database on Linux and using datapump import the data from the source. The parameter are not much different, the memory_target set to 1000m on Linux, we use sga_target on Aix which is 700mb. The db_file_multiblock_read_count on AIX, it is 128 on Linux ( auto set).
>
> Joan
>
> From: Frits Hoogland [mailto:frits.hoogland_at_gmail.com]
> Sent: Friday, March 22, 2013 2:07 PM
> To: david.barbour1_at_gmail.com
> Cc: Hsieh, Joan; oracle_l
> Subject: Re: linux Async io
>
> A sane beginning would be to start with source platform and version and hardware layout en destination specifications. And parameters of both instances.
>
> Then look at both (source and destionation) execution plans.
>
> Then run the critical sql's on both platforms with SQL trace at level 8, and compare them.
>
> Frits Hoogland
>
> http://fritshoogland.wordpress.com<http://fritshoogland.wordpress.com/
> > frits.hoogland_at_gmail.com<mailto:frits.hoogland_at_gmail.com>
> +31 6 53569942<tel:+31%206%2053569942>
>
> Op 22 mrt. 2013 om 18:55 heeft David Barbour
> <david.barbour1_at_gmail.com<mailto:david.barbour1_at_gmail.com>> het
> volgende
> geschreven:
> Joan,
>
> It appears it is - but may not be very efficient at this point. What version of Oracle and Linux are you using? What type of filesystem/disk/etc. (Not just NetApps - ASM, OCFS, etc.)?
>
> On Fri, Mar 22, 2013 at 11:47 AM, Hsieh, Joan <Joan.Hsieh_at_tufts.edu<mailto:Joan.Hsieh_at_tufts.edu>> wrote:
>
> Hi,
> We are migrating DW database from AIX to linux, the online transaction is ok compared to AIX. But the batch job is 35% slower than AIX. Of course, the architecture are different, the storage is Netapps on Linux. From the awa report. 60% time is user IO waiting. I'm not sure how to read the following information, is it async io enabled?
>
> Thank,
>
> Joan
>
> dwdb-prod-01:c0ra1e)SDWPRD:/oracle/product/11.2.0.3/bin<http://11.2.0.
> 3/bin>
>> cat /proc/slabinfo | grep kio
> kioctx 56 80 384 10 1 : tunables 54 27 8 :
> slabdata 8 8 0
> kiocb 0 0 256 15 1 : tunables 120 60 8 :
> slabdata 0 0 0
> dwdb-prod-01:c0ra1e)SDWPRD:/oracle/product/11.2.0.3/<http://11.2.0.3/>
>
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Received on Fri Mar 22 2013 - 21:38:14 CET