Re: Large pages

From: Noons <>
Date: Mon, 19 Nov 2012 20:53:47 -0800 (PST)
Message-ID: <>

On Nov 15, 4:05 am, joel garry <> wrote:

> Don't apologize; blog!  There is surely a shortage of excellent Oracle
> AIX exposition.

On a totally different note, nothing to do with Jonathan's point whatsoever:

...and a lot of plain, DEAD WRONG lore in the so-called "community" forums...

I've lost count of the number of times I've heard "IBM experts" and other such claiming in forums that to get performance with Oracle in Aix 5L (and later) one needs to mount all jfs2 file systems storing database data with the "cio" option.

Which promptly removes any use of the file system buffer cache for ALL Unix commands involving file IO on ANY file in such file systems!

It could have been true before 10g Oracle. Since then, all we have to do is turn on filesystemio_options = SETALL and bingo, ALL Oracle data files (and ONLY those) located on jfs2 filesystems will be opened with the cio option. While using the Aix commands on them to copy/move/backup will use the normal file system cache and not drop the speed of access.

But what do I see everywhere I go with Oracle in Aix, regardless of what version? All jfs2 file systems mounted with cio option. Now, THERE is a "rule of thumb" GUARANTEED to destroy ALL IO performance other than through Oracle... (groan...) Received on Tue Nov 20 2012 - 05:53:47 CET

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