[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?

[Wendy Cheng]

Thai Duong wrote:

> Hi there,
>
> I'm using Red Hat GFS 6.0 as the cluster file system for a 4-node 
> Oracle RAC 9.2.0.7 <http://9.2.0.7>, each node is running RHAS 3 
> Update 6. There're probably a lot of benefits in using direct I/O 
> and/or async I/O with Oracle9i RAC. RH GFS itself supports direct I/O 
> regardless of the application running on top of it. I have asked a 
> Oracle Support Service guy and he confirms that we can use direct I/O 
> feature of RH GFS but he doest have information about async I/O. May I 
> turn on direct I/O and/or async I/O (I mean recompile Oracle to 
> support async I/O) when using GFS as the cluster file system for 
> Oracle9i RAC? Do you have any experience with this? Please help.
>
Direct IO is ok for both GFS 6.0 and GFS 6.1. Asyn IO is enabled in >=  
RHEL 4 (GFS 6.1) Update 3 (in beta testing).

Also there could have deadlock issues with Direct IO with Oracle under 
GFS 6.1 (<= RHEL 4 U2).

-- Wendy