Re: Problems with large pages on AIX after upgrading to

From: patrick obrien <>
Date: Thu, 4 Mar 2010 10:16:13 -0800 (PST)
Message-ID: <>

did you get any kind of aix error? errpt -a, if so, ibm might have a fix for this. POB.
  • On Thu, 3/4/10, Allen, Brandon <> wrote:

From: Allen, Brandon <> Subject: Problems with large pages on AIX after upgrading to To: "oracle-l-freelists" <> Date: Thursday, March 4, 2010, 9:02 AM

Hi List,   Just a heads up since I couldn’t find this documented on MOS or anywhere else – I’ve been using large pages for my Oracle databases on AIX 5.3 ML7 for years with no problems.  Recently I upgraded to, followed by one-off patch 7226548 for a known issue where AIX large pages don’t work anymore with  Unfortunately, even with patch 7226548 installed, I found that large pages still weren’t working.  I had to make two changes to work around the problem:   1)      Set the new environment variable ORACLE_SGA_PGSZ=16m  (this is documented as a work around for prior to the release of the patch for bug 7226548, but for some reason it is apparently still required in my case even after installing patch 7226548, probably due to some change in PSU 3) 2)      Increase lgpg_regions by 1; For years, I had successfully used the published formula for determining the value of lgpg_regions, which came out to 64 large pages for my 1GB SGA, but after upgrading to with patch 7226548, I had to increase lgpg_regions from 64 to 65 in order to startup the database, otherwise it would fail with  "ORA-27102: out of memory"   I’ve filed a new bug (9412044) with Oracle for these problems, so hopefully they’ll get the relevant notes updated on MOS soon.  Anyone else encountered the same problems?   Regards, Brandon Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it.

-- Received on Thu Mar 04 2010 - 12:16:13 CST

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