RE: Is filesystemio_options relevant when the database is on ASM ?

  • From: "Hameed, Amir" <Amir.Hameed@xxxxxxxxx>
  • To: "mwf@xxxxxxxx" <mwf@xxxxxxxx>, "frits.hoogland@xxxxxxxxx" <frits.hoogland@xxxxxxxxx>, "Hemant-K.Chitale@xxxxxx" <Hemant-K.Chitale@xxxxxx>
  • Date: Thu, 16 Oct 2014 15:13:23 +0000

We started using DNFS about two years ago (11gR2). I did raise this question 
with Oracle through an SR, that is, whether or not the FILESYSTEMIO_OPTIONS 
parameter needs to be set for DNFS type environments, and I was told that it 
was not needed as the DNFS code bypasses the filesystemio_options code. 
However, the Oracle kernel group also suggested that as a general best 
practice, it should be set to setall as it is not going to impact DNFS type 
configurations.

From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On 
Behalf Of Mark W. Farnham
Sent: Thursday, October 16, 2014 11:04 AM
To: frits.hoogland@xxxxxxxxx; Hemant-K.Chitale@xxxxxx
Cc: 'ORACLE-L'
Subject: RE: Is filesystemio_options relevant when the database is on ASM ?

The immediate side question becomes: Can we catalog any situations in which the 
'setall' setting is suboptimal?

IF there are no known situations where 'setall' is harmful, then I believe it 
would be wise to set it as standard operating procedure.
IF there are some known situations where 'setall' is suboptimal, then the 
catalog of exceptions would be gold.
(Setting it when it does no harm operationally being irrelevant beyond a few 
microseconds at database restart to parse the parameter.)

mwf

From: oracle-l-bounce@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx> 
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Frits Hoogland
Sent: Thursday, October 16, 2014 5:35 AM
To: Hemant-K.Chitale@xxxxxx<mailto:Hemant-K.Chitale@xxxxxx>
Cc: ORACLE-L
Subject: Re: Is filesystemio_options relevant when the database is on ASM ?

Hi Hermant,

With version 11 ASM (ASM needs to be available on the node where the database 
lives), and when using Exadata, filesystemio_options is NOT relevant to the 
database processes when using files (redo, data, temp) on local ASM managed 
devices.
I am not sure with version 12, probably the locality between the device and the 
ASM instance which it manages is relevant.

When using NFS underneath ASM, I've witnessed filesystemio_options being 
honoured by the database, which means it needs setting it to 'setall' for the 
combination AIO+DIO. Which makes sense, because you need to create a file on a 
(NFS) filesystem to be used as ASM disk device.

Frits Hoogland

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On 16 Oct 2014, at 11:25, Chitale, Hemant K 
<Hemant-K.Chitale@xxxxxx<mailto:Hemant-K.Chitale@xxxxxx>> wrote:


Is filesystemio_options relevant when the database is on ASM ?


Hemant K Chitale



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