| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
 |
 | |||
| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
|
| |||
Home -> Community -> Mailing Lists -> Oracle-L -> RE: shutdown abort / startup restrict / shutdown vs. shutdown imm
shutdown abort / startup restrict / shutdown vs. shutdown immediateI 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-----
Sent: Tuesday, July 23, 2002 1:21 PM
To: Multiple recipients of list ORACLE-L
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 Tue Jul 23 2002 - 18:03:47 CDT
(or the name of mailing list you want to be removed from). You may
also send the HELP command for other information (like subscribing).
 |
 |