RE: AIX - Processor Folding; schedo -o vpm_xvcpus; good with Oracle??

From: Scott Heisey <oraracdba_at_yahoo.com>
Date: Thu, 7 Apr 2011 18:25:42 -0600
Message-ID: <002101cbf583$7f4d3bc0$7de7b340$_at_com>

Short answer, Do what Oracle wants. Database support usually comes from Oracle not IBM.  

Long answer, I have not seen folding on or off as an issue. At some time in the past there were some scheduling issues when processor folding was enabled and would cause nodes to reboot in a RAC environment on AIX. Scheduling was in issue with 10.2 clusterware and was exacerbated by enabling processor folding. In 10.2.0.4 there were some changes to the clusterware so scheduling was not so much an issue and there were more changes in 11.1.0.7 as well. All I can say is that I have not seen folding as an issue to Oracle with 10.2.0.4 and later but that is no guarantee. This is a dynamic parameter so you can turn it on and off with major impact to the system.  

Scott  

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of patrick obrien
Sent: Thursday, April 07, 2011 3:20 PM
To: oracle-l_at_freelists.org
Subject: AIX - Processor Folding; schedo -o vpm_xvcpus; good with Oracle??  

DBA's,

I run oracle 10 and 11 on several AIX 5300 Lpar'ed Servers.

Should I turn on Processor Folding, schedo -o vpm_xvcpus???

IBM says to turn it on. I've read, Oracle says to leave it off?

This is a huge feature IBM offers, for performance. The ones the really know if this is a good feature, are the dba's in the field.

Thank you,
Patrick.  

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Received on Thu Apr 07 2011 - 19:25:42 CDT