From: RENAULT, François (frenault_at_tf1.fr)
Date: Tue Sep 30 2003 - 11:09:28 CEST
Date: Tue, 30 Sep 2003 11:09:28 +0200 Message-ID: <02C5EC55F2455947B94D57576D35DF80CC53A0@MSGEXS21.tf1.groupetf1.fr> From: "RENAULT, François" <frenault@tf1.fr> Subject: RE: [suse-oracle] enabling async IO
sorry but a i/o is true by default ( nt , unix ...)
linux doesn't have by default a i/o except by adding the library ( some suse,red hat, united linux version now have it )
DISK_ASYNCH_IO
Parameter type Boolean
Default value true
Parameter class Static
Range of values true | false
DISK_ASYNCH_IO controls whether I/O to datafiles, control files, and logfiles is asynchronous (that is, whether parallel server processes can overlap I/O requests with CPU processing during table scans).
If your platform supports asynchronous I/O to disk, Oracle Corporation recommends that you leave this parameter set to its default value. However, if the asynchronous I/O implementation is not stable, you can set this parameter to false to disable asynchronous I/O. If your platform does not support asynchronous I/O to disk, this parameter has no effect.
If you set DISK_ASYNCH_IO to false, then you should also set DBWR_IO_SLAVES to a value other than its default of zero in order to simulate asynchronous I/O.
-----Message d'origine-----
De : Reidy, Ron [mailto:Ron.Reidy@arraybiopharma.com]
Envoyé : lundi 29 septembre 2003 21:05
À : SuSE-oracle@suse.com
Objet : RE: [suse-oracle] enabling async IO
Async IO is not turned on by default (I manually set 'disk_async_io = true' in init.ora after the relink.
From metalink:
cat /proc/slabinfo |grep kio
for E.g
output with async io enabled.
> cat /proc/slabinfo |grep kio
kioctx 270 270 128 9 9 1 : 252 126
kiocb 66080 66080 96 1652 1652 1 : 252 126
kiobuf 236 236 64 4 4 1 : 252 126
oracle@rockjaw:/data2/oast/home>
output with async io disabled
> cat /proc/slabinfo |grep kio
kioctx 0 0 128 0 0 1 : 252 126
kiocb 0 0 96 0 0 1 : 252 126
kiobuf 0 0 64 0 0 1 : 252 126
.
There are 3 caches involved.
The kioctx and kiocb are Async I/O data structures that are defined in aio.h. If it shows a non zero value that means async io is enabled.
If you have the source code loaded, you can review it at:aio.h
These data structures are using to track the I/O requests, and are allocated as part of the __init aio_setup() call in aio.c.
Note: I did not verify the above before turning on async io in the instance.
-----------------
Ron Reidy
Senior DBA
Array BioPharma, Inc.
303.386.1480
-----Original Message-----
From: Eric Raskin [mailto:eraskin@paslists.com]
Sent: Monday, September 29, 2003 12:51 PM
To: Reidy, Ron; SuSE-oracle@suse.com
Subject: RE: [suse-oracle] enabling async IO
Thanks.
Just out of curiosity, how do you know that Async I/O is now turned on and
that it was turned off before? Where can you view the settings/effects?
TIA
Eric Raskin
-----Original Message-----
From: Reidy, Ron [mailto:Ron.Reidy@arraybiopharma.com]
Sent: Monday, September 29, 2003 2:47 PM
To: eraskin@paslists.com; zhu chao; SuSE-oracle@suse.com
Subject: RE: [suse-oracle] enabling async IO
I am using 9.2.0.4.0.
'async_on' may not be a target, but following the directions from Zhu, all
worked for me.
Please see http://www.suse.com/oracle/ before posting
This electronic message transmission is a PRIVATE communication which contains
information which may be confidential or privileged. The information is intended
to be for the use of the individual or entity named above. If you are not the
intended recipient, please be aware that any disclosure, copying, distribution
or use of the contents of this information is prohibited. Please notify the
sender of the delivery error by replying to this message, or notify us by
telephone (877-633-2436, ext. 0), and then delete it from your system.
--
To unsubscribe, email: suse-oracle-unsubscribe@suse.com
For additional commands, email: suse-oracle-help@suse.com
Please see http://www.suse.com/oracle/ before posting
-------------------------------------
Le présent message (y compris tous les éléments attachés) est confidentiel et est destiné à ses seuls destinataires. Si vous
lavez reçu par erreur, merci de lindiquer à son expéditeur par retour et de procéder à sa destruction dans vos systèmes.
Toute utilisation ou diffusion non autorisée de son contenu, en totalité ou en partie, est strictement interdite. Les idées et
opinions présentées dans ce message sont celles de son auteur, et ne représentent pas nécessairement celles de TF1 (et/ou des
entités membres du Groupe TF1).
This message (including any attachments) is confidential and may be privileged. If you have received it by mistake please notify
the sender by return email and delete this message from your system. Any unauthorised use or dissemination of this message in
whole or in part is strictly prohibited. Any views or opinions presented are solely those of its author and do not necessarily
represent those of TF1 (and/or its group companies).
-- To unsubscribe, email: suse-oracle-unsubscribe@suse.com For additional commands, email: suse-oracle-help@suse.com Please see http://www.suse.com/oracle/ before posting
This archive was generated by hypermail 2.1.7 : Tue Sep 30 2003 - 11:12:50 CEST