RE: direct reads and writes on Solaris

From: <>
Date: Fri, 25 Jan 2008 08:38:12 -0500
Message-ID: <>

Very informative links.

Thank you Ukja


"Ukja.dion" <>
Sent by:
Jan 24 2008 06:55 PM
Please respond to

To, "'Oracle L'" <> cc

RE: direct reads and writes on Solaris

Visit following URLs      

From: [] On Behalf Of Dan Norris
Sent: Friday, January 25, 2008 7:14 AM
To: Oracle L
Subject: direct reads and writes on Solaris  

Can someone help me interpret this set of data correctly?

The (vxfs) filesystem is mounted with these options: /db51 on /dev/vx/dsk/oracledg/db18

This is on Solaris 9 (V490, Generic_122300-07) with VxFS 4.1.

I have the following line in a truss of a dedicated server process:

open("/db51/oradata/tccrt1/member_questions_d01.dbf", O_RDWR|O_DSYNC) = 9

I also have the following settings in the DB:

NAME                                 TYPE        VALUE
------------------------------------ ----------- 
disk_asynch_io                       boolean     TRUE
filesystemio_options                 string      ASYNCH

The question(s):
I was expecting to see O_DIRECT in there somehow, but I'm thinking that maybe that's just on Linux, not Solaris. I don't see O_DIRECT listed in the open(2) manual page. I am also wondering if filesystemio_options needs to be "setall" instead of the current setting of "ASYNCH" in order to achieve directIO. Or, am I looking at the wrong thing to determine if directIO is enabled?

Thanks in advance!


Received on Fri Jan 25 2008 - 07:38:12 CST

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