Re: Disk Async IO

  • From: "LS Cheng" <exriscer@xxxxxxxxx>
  • To: bnsarma@xxxxxxxxx
  • Date: Sat, 9 Sep 2006 09:16:07 +0200


I think if you have Veritas Quick I/O it would have similar performance as
RAW Device.

If you have OnlineJFS without the Quick I/O then your parameters is doing
nothing as other suggested. However with Online JFS you can use direct I/O
which has a decent performance, by default direct I/O is not enabled, you
have to modify the mount options.

Both Online JFS and Veritas Quick I/O are very expensive though....


On 9/6/06, BN <bnsarma@xxxxxxxxx> wrote:


I remember reading Oracle Metalink  Notes saying that Disk Async IO is not
supported on HP-UX for Cooked Filesystems.

We have disk_async_io=true for our Database in HP-UX 11.11 , Oracle and 10g Servers.

I would like to ensure that my understanding and setting is right.

Right now we are using 4 dbwr's. I appreciate  your suggestions.

Our UNIX SA says  " Cooked Filesystems have their own Asynchronous
Mechanisim that equally replaces Oracle Async IO"

What Am I missing here

Appreciate your suggestions.

Regards & Thanks

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