On Aug 7, 2:20 pm, Andrea <netsecur..._at_tiscali.it> wrote:
> On 7 Ago, 13:45, hacketta..._at_mac.com wrote:
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> > On 7 Aug, 09:52, Andrea <netsecur..._at_tiscali.it> wrote:
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> > > Hi,
> > > i've read some info on "filesystemio_options" here:http://download-west.oracle.com/docs/cd/B13789_01/server.101/b10752/c...
>
> > > i would like to know if is possible to set Direct I/O for parameter
> > > "filesystemio_options" on hp-ux
>
> > > Someone have experience whit it?
>
> > > thanks
> > > by
> > > andrea
>
> > To enable direct IO on HPUX you need to set certain vxvfs mount
> > options: mincache=direct covosync=direct.
>
> > Seehttp://www.oracle.com/technology/deploy/performance/pdf/TWP_Oracle_HP...
> > for more info. on this topic
>
> thanks very much!
>
> So, you can have experience if this option can really improve
> performance on OLTP db??
> there is some advise for implementing direct IO rather then
> RawDevice ?
>
> thanks- Hide quoted text -
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> - Show quoted text -
You need to differentiate between direct IO (which means bypassing the
file system cache) and asynchronous I/O on RAW devices and similar.
The biggest performance gains are obtained using RAW.
There are HP whitepapers demonstrating this.
--
Sybrand Bakker
Senior Oracle DBA
Received on Tue Aug 07 2007 - 07:53:14 CDT
