Re: AIX 5.2 move from JFS to JFS2

  • From: "David Barbour" <david.barbour1@xxxxxxxxx>
  • To: Patty.Charlebois@xxxxxxxxxxxxxx
  • Date: Wed, 27 Jun 2007 13:37:20 -0400


What version of AIX are you on?  As you're probably aware,  db_block_buffers
is deprecated in favor of db_cache_size.  If you're using Automatic Memory
Management, you need to look at a couple of things, including
pga_aggregate_target, before increasing your cache size.  Best to run a
statspack to get some more input.  Increasing the cache size may help
alleviate your issue, also check your db_file_multiblock_read count.

On 6/27/07, Patty.Charlebois@xxxxxxxxxxxxxx <Patty.Charlebois@xxxxxxxxxxxxxx>

Now that I have upgraded our production systems from to I
can see via truss that Oracle is taking advantage of our newly implemented
JFS2 filesystems and opening the datafiles using CIO.

We are experiencing higher WIO percentages since the upgrade.

My sysadmn has suggested that perhaps I need to increase db_block_buffers
to make up for the lack of buffering at the FS level now that we are using

Does anyone have any experience and/or thoughts regarding this?


This e-mail is confidential, intended solely for the use of the
recipient(s) to whom it was addressed. If you have received it
in error, please do not copy or distribute this e-mail. We ask
that you notify us immediately by replying to the sender and
then delete this e-mail. E-mail sent or received over the
internet may not be secure. You should use caution when sending
e-mail messages containing private and confidential information
or consider other secure means to send the information. If you
have any questions regarding the authenticity or security of
the e-mail you have received please do not hesitate to contact
us at 1-800-265-5615.

Ce message de courriel est confidentiel et s'adresse uniquement
à la personne indiquée.  Si vous l'avez reçu par erreur,
veuillez ne pas copier ni distribuer ce message de courriel.
Nous vous demandons de nous aviser immédiatement en répondant à
l'expéditeur, puis en supprimant ce message.  Les messages
envoyés ou reçus par courriel pourraient ne pas être sécurisés.
Vous devriez être prudent lorsque vous envoyez des messages de
courriel contenant des renseignements confidentiels et privés
ou songer à prendre d'autres moyens sécurisés pour envoyer les
renseignements.  Si vous avez des questions concernant
l'authenticité ou la sécurité d'un courriel que vous avez reçu,
n'hésitez pas à communiquer avec nous au 1 800 265-5615.

Other related posts: