RE: AIX Concurrent I/O for Oracle archive logs
- From: "Allen, Brandon" <Brandon.Allen@xxxxxxxxxxx>
- To: "dbvision@xxxxxxxxxxxx" <dbvision@xxxxxxxxxxxx>, "oracle-l@xxxxxxxxxxxxx" <Oracle-L@xxxxxxxxxxxxx>
- Date: Wed, 26 May 2010 10:42:22 -0700
Hi Nuno,
This system is 9.2.0.8 on AIX 5.3 ML10 and all Oracle data and log files are
currently on a NAS (NFS instead of JFS2). We have filesystemio_options=setall,
and have the data and log files on a file system mounted with the cio option,
but the arc logs on a separate file system that is not mounted with cio. They
are planning to upgrade to 10g someday (their Baan application isn't yet
certified with 11g), but just haven't gotten around to it yet since everything
is running fine on 9i for now (until this recent issue with paging causing
performance problems during log backups).
Yes, we're using Async IO and we probably have too many aio servers (maxservers
= 400 * 8 processors = 3200 total aioservers). The docs I've read say to set
maxservers to 80 at the most, e.g. :
http://public.dhe.ibm.com/partnerworld/pub/whitepaper/162b6.pdf
"limit the maximum number of servers to 10 times the number of disks that are
to be used concurrently, but no more than 80"
We only have 200 datafiles. I've already asked the Unix admins to consider
lowering maxservers in order to free up any excessive resources they may be
consuming.
Thanks,
Brandon
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On
Behalf Of Nuno Souto
IF - you are running >= AIX 5.2L
IF - you are running >= Oracle 10g
IF - all your file systems are JFS2
. . .
Have you/are you using AIO?
One caution: AIX by default does not configure enough started AIO server
processes to satisfy Oracle's demands. Jack it up to at least twice the total
number of datafiles.
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