RE: Async and Direct I/O On Solaris using VXFS

From: rajesh koppada <>
Date: Tue, 28 Jun 2011 15:02:12 +0000
Message-ID: <BAY158-w2124DAF80CB355BB7636FCB6560_at_phx.gbl>

I was following the below link and tracing the systems calls ,  

We are using oracle version on VXFS file systems on Sun solaris  

4294/1:         open("/users/oracle/undofile/undotbs01.dbf", O_RDWR|O_DSYNC) = 10
4294/1:         ioctl(257, (('V'<<24)|('X'<<16)|('F'<<8)|1), 0x00000004) = 0

any idea how to intepert this ioctl arguments ?? Just to ensure we are getting Direct I/O on VXFS file systems.  

Date: Mon, 27 Jun 2011 15:17:12 -0700
Subject: Re: Async and Direct I/O On Solaris using VXFS


The tool "directiostat" looks pretty cool for sparc, on page

direct link at

On Mon, Jun 27, 2011 at 2:57 PM, kyle Hailey <> wrote:

What platform are you on? For direct I/O on solaris check out


Another good reference

2011/6/27 rajesh koppada <>


How can i confirm that oracle will be doing Direct I/O and Asynchronous i/o with following options. Database FILESYSTEMIO_OPTIONS is set to ALL which means to use, setall - Enables both ASYNC and DIRECT IO we are using VERITAS volume manager 5.0 with VXFS filesystems(We don't have QIO or ODM) and file system mount options are set as follows mincache=direct and conovsync=direct
Will Oracle is going to use both direct i/o and asynchronous i/o with these file system options. How can we ensure i am getting direct i/o and Async i/o ? can we enable some trace or something just to ensure we are getting both?  


Received on Tue Jun 28 2011 - 10:02:12 CDT

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