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Re: A really strange one..

From: Best, David <>
Date: Wed, 26 Sep 2007 15:38:28 -0400
Message-ID: <>

There is a script in oracle_home/bin. Its called sysresv and will list the shared memory and semaphores for a Sid. Useful for tracking down what is used for a particular Sid if your are running multiple databases out of the same home. See note 153961.1 for details if interested.

-----Original Message-----
From: <> To: oracle-l <>
Sent: Wed Sep 26 14:43:00 2007
Subject: RE: A really strange one..

I have seen it many times, mostly on Linux, sometimes on AIX, rarely on Solaris. Looking for shared memory segments that were not released, and freeing them (or rebooting) is the normal fix. I believe there is a lock file in $OH/dbs by default that might need to be removed, but the name of the file escapes me.  

From: [] On Behalf Of Andrew Kerber Sent: Wednesday, September 26, 2007 11:36 AM To: oracle-l
Subject: A really strange one..  

Ok, I just ran into a strange one this morning. US central time that is.

We are moving our clustered databases to new servers, and we put one database onto the new hardware for initial testing. We restored from a backup, and got both instances running. Today when I did a

ps -ef | grep pmon

I saw two pmon processes going for the single instance. I have no idea what could have caused that. So I set my oracle_sid, path, oracle_Home and shutdown the instance. What do you know, there was still one pmon process running. I did a kill -9 on that one.

Then I go to start the instance again. And I get this error: ORA 01081 "cannot start already-running ORACLE - shut it down first"

I did a ps -ef | grep oracle, didnt get anything (except my user process of course).

I finally googled and found one possibility, a locked shared memory segment.

Sure enough

ipcs -a | grep dba

returned a large segment of memory that was still locked. So I ran this (found on the same site) and released it:

ipcs -a | grep dba | perl -ane 'system "ipcrm -$F[0] $F[1]"'

My question is, has anyone seen this before, or know what causes it?

Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'
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Received on Wed Sep 26 2007 - 14:38:28 CDT

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