Re: Oracle 8.1 on AIX 5.3



Yes, it's safe. The new values don't take effect until you reboot.

On the question of whether to wait for the patch: If you're maxing out you
maxservers/reqs, the system is telling you
that you need more. Although the patch will, indeed, clear up this error,
I'm a great believer in listening to what
systems say they need.

There's just my earlier caveat about memory. I think you said you had ten
gigs. Give each AIO server about
64K. Do the math, and run some vmstats. If you 1) Have enough pages on the
freelist to accommodate the
change, then you're okay, and 2) Are you scanning/freeing memory to
maintain that freelist? Divide the sr/fr
columns by the number of CPUs in the system. If those rates are <500,
you're probably okay.

Best Regards,

Mark J. Ray
Advisory IT Specialist
AIX Performance
p Series Team
Global Technology Services
IBM
email: raym@xxxxxxxxxx





AIX
<aix@xxxxxxxxxxxx
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Discussion List cc
<aix-l@Princeton.
EDU> Subject
Re: Oracle 8.1 on AIX 5.3

09/23/2009 08:37
PM


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<aix-l@Princeton.
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Is it safe to change the maxservers and minservers values with aioo command
While database actively writing to disk?


We might apply the oracle patch rather than increasing any of those
numbers.
I believe increasing those numbers are for bypassing the Oracle bug,
But once we install the Oracle patch we shouldn't have any problem.

-----Original Message-----
From: IBM AIX Discussion List [mailto:aix-l@xxxxxxxxxxxxx] On Behalf Of
Mark
J Ray
Sent: Tuesday, September 22, 2009 4:30 PM
To: aix-l@xxxxxxxxxxxxx
Subject: Re: Oracle 8.1 on AIX 5.3

There is a notorious bug in Oracle 8 - 9 that requires that the AIO request
queue be adequate, otherwise you'll get
the errors you're seeing. First, if you have 4 CPUs with 300 AIOs per CPU
configured and you see 1200 AIOs
active, you've activated all the aioservers you have configured. I would
bump that number up to 325 - 350
(assuming you have the memory) and then up your AIO "maxreqs" value. Go to
65536 for the value of
AIO Maxreqs for starters (a "smitty aio" is the easiest way to do this in
5.3). If the error recurs, go up to
around 131072. Again, if you're memory constrained, this may be
problematic.

Bear in mind that block 43269 may indeed be bad, so you might have more
than one thing going on.


Best Regards,

Mark J. Ray
Advisory IT Specialist
AIX Performance
p Series Team
Global Technology Services
IBM
Phone: 1-860-710-6145
email: raym@xxxxxxxxxx





Bill Verzal
<bjverzal@xxxxxxx
OM> To
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<aix-l@Princeton.
EDU> Subject
Re: Oracle 8.1 on AIX 5.3

09/22/2009 03:22
PM


Please respond to
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<aix-l@Princeton.
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Probably more like /etc/tunables. You can also look

at /usr/samples/kernel/vmtune, if installed.


--- On Tue, 9/22/09, Little Guru <aix@xxxxxxxxxxxxxx> wrote:


From: Little Guru <aix@xxxxxxxxxxxxxx>

Subject: Oracle 8.1 on AIX 5.3

To: aix-l@xxxxxxxxxxxxx

Date: Tuesday, September 22, 2009, 3:07 PM


We have upgraded one of our servers from 5.1 to 5.3

and our users experiencing problem with one of the oracle

instances. here is the error:


ORA-01115: IO error reading block from file 14 (block # 43269)

ORA-01110: data file 14: '/Path_to_dbf_file/somefile.dbf'

ORA-27091: skgfqio: unable to queue I/O

IBM AIX RISC System/6000 Error: 5: I/O error]



we are not seeing any error either in errpt or oracle database.


with a bit research we came up with aioo setting but before changing

any thing I need to know which odm file contain the data for aioo

setting.

so I can extract the info from mksysb and see if that has been changed.


pstat -a | grep aio | wc -l returns 1200 aioserver

maxservers is 300 and server has 4 cpu


Thanks



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