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Re: Oracle on AIX hangs

From: Fuad Arshad <>
Date: Fri, 27 Jan 2006 04:09:51 -0800 (PST)
Message-ID: <>

what type of connect are you erforming is it an application conenction (wensphere etc)   or just plain sqlplus connection.
  seems like you box is unable to handle the resources you are requesting.   or there are some rogue statements in the app code that you are tryingto run.   from 8.1.7 to 9.2 there were alot of optimizer changes that mess up a lot of code if not tested properly.   it seems that you upgraded and migrated at the same time.   check the sql explain plans.
  maybe you might want ot change optimizer_features_enable to and see if that helps you in the short term.   

"Allen, Brandon" <> wrote:

      Anyone else seen anything like this?    

  Oracle, AIX 5.2 ML7    

  Recently migrated to new server, from Oracle 8.1.7 & AIX 5.1, and since moving to the new server we've had a few instances of horrible performance where hdisk0 is pegged at 100% utilization. When this happens it takes 60 seconds just to establish a telnet connection and all Oracle sessions, as well as new connection attempts just hang indefinitely. We can't even get a "conn / as sysdba" connection so we can't get a hanganalyze or systemstate dump.    

  After we killed all database server processes (not the background processes), the hdisk0 utilization dropped down to zero, but then as soon as we try to connect again, the connection attempt hangs and hdisk0 goes back to 100%. We can't even shutdown the instance since we can't connect so we have to kill it, and then the problem goes away and does not come back when the instance is restarted . . . until the next time, which may be days or weeks later. We haven't been able to identify any pattern to the occurrences yet.    

  I've been all over Google and Metalink with no luck.    

  Any ideas?    

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Received on Fri Jan 27 2006 - 06:09:51 CST

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