Re: Is Async IO being Used or NOT ?

From: Deepak Sharma <>
Date: Thu, 6 Nov 2008 15:12:01 -0800 (PST)
Message-ID: <>

One way to see if ODM is installed or not is to verify /dev/odm  (it's a directory):

$ ls -l /dev/odm
total 0
-rw-rw-rw-   1 root     system            0 Nov 06 17:08 cluster
-rw-rw-rw-   1 root     system            0 Nov 06 17:08 ctl
-rw-rw-rw-   1 root     system            0 Nov 06 17:08 ktrace
-rw-rw-rw-   1 root     system            0 Nov 06 17:08 stats

As I understand, ODM was developed by Veritas and Oracle together, but as for the setup it probably needs to go through Veritas.


Sent: Thursday, November 6, 2008 1:33:13 AM
Subject: RE: Is Async IO being Used or NOT ?

Some basic Qs on ODM
LSC, Folksbelow
	1. How is it possible to check if ODM(Oracle Disk Manager)  is setup or NOT on the machine?
	2. Does ODM need a Separate Setup on HP-VXFS? .. Is it separated Licensed? If so by who - Oracle Corp or HP?
Am assuming that HP-UX
uses VXFS by Default.
Cheers & Thanks V

From:LS Cheng

aio is only posible with
raw devices in hp-ux unless you use odm on vxfs


On Wed, Nov 5, 2008 at 8:35 AM, VIVEK_SHARMA <> wrote:
Need to find out if Async IO is setup &
working or NOT in our Performance Benchmark Setup.
Qs 1 - What HP-UX
Command gives the existing filesystemio_options settings for the mounted filesystem ?
NOTE - Init.ora parameter disk_async_io=true
Qs 2  For Async IO to work, is there a
dependency or NOT on the existence of the file "/dev/async" ?  This file does NOT exist Currently
 Is the presence of this file merely to suppress the below Error Message
in Oracle Trace files.
Oracle Trace
Files currently contain the Message:- 
Error - File '/dev/async' not present :
Link -
Existing Configuration:-
name:    HP-UX
name:      SPEHPPA1
Release:        B.11.11
Will provide any info needed . Cheers
& Thanks V much
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Received on Thu Nov 06 2008 - 17:12:01 CST

Original text of this message