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Home -> Community -> Mailing Lists -> Oracle-L -> RE: shutdown abort / startup restrict / shutdown vs. shutdown imam
shutdown abort / startup restrict / shutdown vs. shutdown immediateLet me
rephrase my previous response (leaving out "I've been doing this for years
and it has always worked', which is the case) .......... There have been a
number of occasions where it has become necessary to invoke the 'startup
force restrict, shutdown normal ' option. It is obviously not the desired
method because it ain't normal ... and , incidentally I failed to mention
that my cold backup shutdown is preceded by an 'alter system checkpoint' .
The point being that Oracle's inherent ability to recover after an abnormal
shutdown has been proven, in my experience, successful .... therefore I
have made the decision that prior to a cold backup .... I will checkpoint,
abort, startup and shutdown normal .... thereby feeling confident that I
have a backup of a database in a stable, consistent state. Meanwhile, to
remain analogous, I will upgrade to the new and improved 'Run Flat' tire
technology.
-----Original Message-----
Sent: Tuesday, July 23, 2002 5:33 PM
To: Multiple recipients of list ORACLE-L
I have steel belted radial tires on my car that are supposed to be puncture resistant. Is this a good reason for me to go out of my way to drive by a construction site every morning? By my way of thinking, no. If my regular road is blocked and I have no alternative, then I will drive by the construction site reasonably confident that the debris will not puncture my tires. If I'm in a big hurry and driving by the construction site is significantly quicker, then I will consider it. But, I don't go out of my way looking for trouble.
Does anyone have a better argument than "I've been doing this for years and
it has always worked?"
Kevin Kennedy
First Point Energy Corporation
-----Original Message-----
From: Christopher Royce [mailto:ffm9np_at_onsemi.com]
Sent: Tuesday, July 23, 2002 4:04 PM
To: Multiple recipients of list ORACLE-L
Subject: RE: shutdown abort / startup restrict / shutdown vs. shutdown imm
I would have to agree with Rich ....... For years I have been using
startup force restrict, shutdown normal prior to cold backups .... with the
assumption that I want a completely 'static' and normal shutdown prior to
the backup. Because of applications that maintain persistent connections,
daemons that re-connect, etc. etc. that do not 'let loose' of the database
..... I have on numerous occasions had shutdown immediate 'hang'. I believe
the operative process is the startup force restrict that enables
auto-recovery and then the normal shutdown. I have never had an subsequent
problems. Why chance any anomalous conditions that could be introduced to
the recovery process or rebuild of a database.
-----Original Message-----
From: root_at_fatcity.com [mailto:root_at_fatcity.com]On Behalf Of Gesler, Rich
Sent: Tuesday, July 23, 2002 1:21 PM
To: Multiple recipients of list ORACLE-L
Subject: RE: shutdown abort / startup restrict / shutdown vs. shutdown imm
You are assuming that shutdown immediate is a fix amount of time. If
there is a lot to rollback it may take longer to rollback (via shutdown
immediate) than the parallel crash recovery (the startup after a shutdown
abort).
It depends on the system. The question was why is immediate better than
abort? I wanted to challenge the assumption that it is not safe to do an
abort. You are relying on Oracle's recovery mechanisms which I have to
assume are reliable. It is after all one of the reasons I prefer Oracle.
Well.....
I'll agree with you only on the basis that shutdown immediate sometimes
hangs and in those cases it is quicker to do the abort/start/shut normal
combination. However, based on a quick review of my logs from last night
(cold backup), I see the shutdown immediate took about 12 seconds. The
following startup (which needed no recovery) took about a minute.
Had I used the shut abort technique, I expect I would have seen, let's say 5 seconds for the shut abort, 60 seconds or so for the startup restricted, then about 12 seconds for the shutdown normal.
Hmmm. Doesn't seem so cut and dried to me. I think I'll keep using my shutdown script that tries shutdown immediate and only does the abort, etc. if immediate takes too long. At this site, the shutdown immediate only seems to fail about once a month. I can live with that unless someone comes up with a more compelling reason why the shutdown abort is better than a shutdown immediate. So far, all I've seen is the argument that shutdown abort is not evil -- I'm not one who thinks it is evil, I'm just not convinced that it is somehow better.
Kevin Kennedy
First Point Energy Corporation
-----Original Message-----
From: Gesler, Rich [mailto:RGesler_at_lexington.com]
Sent: Tuesday, July 23, 2002 11:14 AM
To: Multiple recipients of list ORACLE-L
Subject: RE: shutdown abort / startup restrict / shutdown vs. shutdown
imm
I don't necessarily agree that shutdown immediate is quicker. If you force a checkpoint prior to the shutdown abort the subsequent crash recovery upon startup is usually pretty fast. Parallel recovery could be a factor as well.
For openers, shutdown immediate is generally quicker than the combination of shutdown-abort/startup-restrict/shutdown-normal. It is also gentler. Consider the analogy of shutting down a Windows desktop computer. Is it preferable to do a standard software shutdown (and maybe tell Windows that you really want to end that hung process) or is it preferable to yank the plug out of the wall then plug it back in again, start up the machine, then shut it down gracefully? I always try to shut Windows down gracefully and only pull the plug when the damn thing is too stupid or brain dead to figure out what shutdown means. I do the same with Oracle.
Kevin Kennedy
First Point Energy Corporation
-----Original Message-----
From: Jacques Kilchoer [mailto:Jacques.Kilchoer_at_quest.com]
Sent: Monday, July 22, 2002 7:53 PM
To: Multiple recipients of list ORACLE-L
Subject: shutdown abort / startup restrict / shutdown vs. shutdown
immedia
> -----Original Message-----
> From: April Wells [mailto:awells_at_csedge.com]
>
> The solutions (the ones that I got) aren't good ones.
>
> Shutdown abort/startup restricted/ shutdown immediate... (a
'VALID
> solution'???)
This might be a naive question, but why is
-> shutdown immediate
better than
-> shutdown abort / startup restrict / shutdown normal ?
(That is assuming of course that no user / job will try to sneak
in after you do the startup restrict)
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Christopher Royce INET: ffm9np_at_onsemi.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-LReceived on Wed Jul 24 2002 - 18:58:51 CDT
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