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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Shutdown Abort
Well said, and I hope the definitive word on this topic, to be dusted off whenever someone revives this discussion.
Does anyone really think that Oracle could have succeeded if power failures or other sudden, unplanned instance terminations threatened data integrity?
Paul Baumgartel
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From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Robert Freeman
Sent: Tuesday, July 03, 2007 12:13 PM
To: oracle-l_at_freelists.org
Subject: RE: Shutdown Abort
Anything is possible given the right set of conditions. Clearly there is an issue with fsck in AIX5L that can cause problems with temporary tablespace temp files. This same problem would seem to exist when doing a shutdown immediate too. So if one were to do a shutdown abort, and reboot the system and have this failure occur, one might well jump to the conclusion that it's a problem with shutdown abort, when in fact it is not.
So there may be other OS interactions that happen in very odd cases that might cause it appear that a shutdown abort is the issue when it is, in reality, something else. Also there could be bugs present anywhere in the configuration (OS, firmware, etc..) that could cause IO corruption given the right conditions. Then there is the possibility of something running in the background of the OS that caused the problem, who is to know? The bottom line is that you are supposed to be able to pull the PLUG on the thing, and expect that it will come up without help *every* *single* time (assuming that pulling the plug didn't take out a physical disk for some reason).
I think you are spot on that this was not a controlled test, so anything could have caused it. In my mind, if it's not reproducable, then there is something about the test that was not controlled. The exact set of conditions needs to be known and reproducable to call a test controlled.
The OP's problem might well have happened with a shutdown immediate, there is no way of telling and so blaming shutdown abort is jumping to conclusions that are not supported by any hard facts other than the fact that one of the actions performed was a shutdown abort. How do we know it wasn't the startup command that was at fault?? This test makes shutdown abort a suspect but not a criminal. If you can replicate the problem consistently, then we have something to work with, and I'd LOVE to see your results.
I guess my point of view is that you are as likely to find a bug with shutdown immediate as you are with shutdown abort, so do we just not shutdown the database at all because there *might* be a bug? All other things being equal, shutdown abort should not have negative impacts on your database, and if it does, it's a bug. Besides, by the time I go production on any given system, I've done a shutdown abort enough times on test and development that it should be exercised pretty well. You can't spend your life worrying about the bugs that *might* be there (there are enough real ones to contend with!!), that is what backup strategies are for.
Finally the *body* of experience here seems to be that shutdown abort works, and is perfectly safe. I've yet to see one case where anyone can reliably replicate a shutdown abort bug in 9i or 10g that is exclusive to shutdown abort. If anyone can provide a reproducible test case of shutdown abort failure, please let me know.
RF
Robert G. Freeman
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-----Original Message-----
From: Joel.Patterson_at_crowley.com [mailto:Joel.Patterson_at_crowley.com]
Sent: Tuesday, July 03, 2007 9:47 AM
To: robertgfreeman_at_yahoo.com; oracle-l_at_freelists.org
Subject: RE: Shutdown Abort
I agree. It was very unusual - but apparently possible. My original note sided with immediate, but if that was unacceptable, I would use abort. ... If Randy claims it has to be a controlled test, then so be it. I would think it quite hard to find exactly what was happening and make it happen.
Joel Patterson
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-- http://www.freelists.org/webpage/oracle-lReceived on Tue Jul 03 2007 - 12:14:35 CDT
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