Re: Oracle Failed to release Shared Memory on Solaris

From: Chuck <ccarson_at_echeeba.com>
Date: Wed, 26 Mar 2003 12:08:57 -0800
Message-ID: <3E8208D9.30408@echeeba.com>

Yong Huang wrote:

> Chuck <ccarson_at_echeeba.com> wrote in message news:<3E80FBA5.3010800_at_echeeba.com>...
> 

>>I was cloning a database by using a recent hot backup via the following
>>steps:
>>
>>1) copy datafiles into correct locations
>>2) startup mount
>>3) recover database using backup controlfile until cancel
>>4) after desired archived logs are applied I type cancel
>>5) alter database open resetlogs
>>
>>I then did a shutdown of the instance, however, the sahred memory
>>segments for oracle were not released. I was unable to startup a new
>>instance not try and shutdown the previous instance again. I have to
>>explictly remove the shared memory segments (using ipcrm as the oracle user)
>>
>>Once this was done I could start the instance back up.
>>
>>Just curious why this occured, and if it is related to any memory/sga
>>configurations. I had just changed the hard limit for open file
>>descriptors to 4096 from 1024.
>>
>>Thanks,
>>CC

> 
> 
> If you can reproduce, it must be an Oracle bug. If you can't, well,
> ask if anybody kill'ed -9 on pmon, or just keep doing ipcrm. SysV IPC
> is notorious in not removing shared memory segment automatically. So
> the programmer has to be careful making sure it's removed before the
> process exits. If somebody does a kill -9 on pmon, then it's not
> Oracle's fault since that signal can't be caught by the process to
> clean up the shared memory.
> 
> There shouldn't be any relationship between increasing file descriptor
> limit and not removing shared memory.
> 
> BTW, how many shared memory segments are for this instance? Before
> Solaris 8, do /usr/proc/bin/pmap [anyoracleprocess] | grep -c shmid.
> On Solaris 8, look at the line [ anon ] below [ heap ] (there may be
> another bug filed on this).
> 
> Yong Huang

Yes, it is consistent, everytime I shutdown the database instance down, either shutdown normal or shutdown immediate it does this. One other really odd thing is this:

When I first start the instance up remote clients are unable to connect for about 5 minutes even though the database is open and the listener has been started. It is very odd, nothing will be logged, etc...

I have an open TAR so I will see what oracle says.

Thanks,
-Chuck

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