Re: Large pages

From: Noons <>
Date: Thu, 22 Nov 2012 19:26:39 -0800 (PST)
Message-ID: <>

On Nov 23, 7:59 am, wrote:

> Yep, that's what I was trying to achieve. Thanks for testing this, I'll be sure to remember this if we ever get to upgrade AIX - as of now we're on AIX 5.3 ML08, so I cannot even get to play with 11gR2.

One thing: you don't need 11gr2 for Aix 7.1. works perfectly well, I have it here. Although it isn't *officially* supported. The only thing I found in 10g doesn't work with Aix 7.1 is largepages and again that might have been an error of mine. Everything else seems to work perfectly fine. In fact that's how I upgraded most of my dbs:
upgrade Aix to 7.1, start instance in 10g, use dbua to upgrade it to 11g.
Strangely enough, dbua 11g logs in to the database before it starts its upgrade. How on earth do they expect it to be up if it is being upgraded? (rolling eyes...)
I had to leave the 10g ORACLE_HOME intact, with the db running. dbua was then run from the 11g ORACLE_HOME and proceeded to do all the transformations to the db and changes to ORACLE_BASE from 10g setup to 11g.

> ( I say *if* we ever get to upgrade: These AIX boxes also host some Oracle databases (don't laugh), which we cannot upgrade because an application based on Webdb 2.2 - stop that laughter, I said! )

Aye.... That was my first battle here, nearly 6 years ago. Had everything and the kitchen sink running, including 7.1 in Windows NT 4 server! Took me a couple of years to get EVERYTHING in 10g and Aix 5.3. And now it's almost all there in 11gr2 and 7.1. Except for Peoplesoft's HR, - of course, it *HAD* to be an Oracle application...

> BTW I have only made small attempts at looking into large pages on AIX, but your old blog entry on about how to do it is bookmarked for when I finally get the time!

Sure. You don't have to use largepages until you are into VERY large SGAs, >> 10GB. That's where it really makes a difference. I've found it improves overall CPU performance by an average of 10% once a SGA in the tens of GBs gets moved to largepages. And upgrading to Aix 7.1 and Oracle 11gr2 gave me another el-cheapo 15% CPU gain (on Power 6 h/ w)! I've got the Unix performance graphic to show it in the SydneyOracle meetup library, "11g Upgrade adventure" presentation: Received on Fri Nov 23 2012 - 04:26:39 CET

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