[Linux-cluster] May I turn on direct I/O and/or async I/O when using GFS as the cluster file system for Oracle9i RAC?

Brian Long brilong at cisco.com
Fri Feb 17 16:45:12 UTC 2006

On Mon, 2006-02-13 at 13:54 -0500, Wendy Cheng wrote:
> Thai Duong wrote:
> > Hi Wendy,
> >
> > Thx for the information. I'll turn on direct I/O on my system. Do you 
> > have any information about how many percent I should gain in term of 
> > I/O performance when turning direct I/O on in general and with Oracle 
> > RAC in particular?
> >
> Our performance group did pass the numbers around sometime ago - the 
> gain seemed to be quite positive but I don't remember the details. On 
> the other hand, do remember this is not a frequent execution code path 
> so try to take the switching steps slowly (i.e. make sure you have 
> backup plan, etc, particularly on GFS 6.0 system).


Any change these performance numbers could be shared with the list?



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