zfs discuss - Mar 2010 - ZFS error while enabling DIRECT_IO for the DB chunks

Hi,

We are using Solaris 10 update 7 with ZFS file system.And using the machine for
informix db.

Solaris Patch level Generic_142900-02 (Dec 09 PatchCluster release)

Informix DB version 11.5FC6


We are facing an issue while enabling DIRECT_IO for the DB chunks.

The error message which appears in the online.log file is "Direct I/O
cannot be used for the chunk file <file_name>"

Kindly help me in this regard .How can I overcome this
-- 
This message posted from opensolaris.org

On Thu, 11 Mar 2010, Kashif Mumtaz wrote:
>
> We are facing an issue while enabling DIRECT_IO for the DB chunks.
>
> The error message which appears in the online.log file is "Direct I/O
cannot be used for the chunk file <file_name>"
>
> Kindly help me in this regard .How can I overcome this
ZFS does not support DIRECT_IO.  UFS does.

Bob
--
Bob Friesenhahn
bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/

On Mar 12, 2010, at 6:31 AM, Bob Friesenhahn wrote:
> On Thu, 11 Mar 2010, Kashif Mumtaz wrote:
>> 
>> We are facing an issue while enabling DIRECT_IO for the DB chunks.
>> 
>> The error message which appears in the online.log file is "Direct
I/O cannot be used for the chunk file <file_name>"
>> 
>> Kindly help me in this regard .How can I overcome this
> 
> ZFS does not support DIRECT_IO.  UFS does.
Also, directio is an overloaded term.  It means different things to different
software. The best approach is to identify your requirements and determine
which features are best suited for those requirements.
 -- richard

ZFS storage and performance consulting at http://www.RichardElling.com
ZFS training on deduplication, NexentaStor, and NAS performance
Atlanta, March 16-18, 2010 http://nexenta-atlanta.eventbrite.com 
Las Vegas, April 29-30, 2010 http://nexenta-vegas.eventbrite.com