[Ocfs-users] OCFS Database too slow

[Varghese Abraham]

Hi Wim,
 I appreciate your reply and I have been following this mailing list very closely for the last 3-4 months.

I am not at all trying to compare between ext3 and ocfs.

The current installation that we are having is dead slow..


We had a previous rac installation (TEST1 ) with OCFS ( kernel e27 , ocfs 1.0.9 , 9.2.0.3 database).
On this old system with OCFS, our performance was beautiful.


I am not able to get even a foot close to the previous systems  ( TEST 1) performance.

Neither am I blaming OCFS.
 After having seen good performance with TEST1 system, I am unable to make out what has gone wrong with the new system although we are on the latest for everything with the new system.

I am sure it is some small issue and that is what I need your help in trying to debug.

R'gds
Varghese Abraham.





-----Original Message-----
From: wim.coekaerts at oracle.com [mailto:wim.coekaerts at oracle.com]
Sent: Friday, July 16, 2004 10:13 AM
To: Varghese Abraham
Cc: ocfs-users at oss.oracle.com
Subject: Re: [Ocfs-users] OCFS Database too slow


yes you are probably comparing local filesystem versus raw or cfs which
is not cached in the OS only in oracle.

this is a story that comes back on this list every few weeks or months
and basically happens because there is a huge misunderstanding on what
the OS filesystem cache provides single node etc etc, it takes time to
explain and I think wehave in the past. could you go through the
archives and look for earlier discussions on this ? 

there is nothing slow, what youa re doing is having a database run that
has a lot of stuff cached in the OS itself on local fielsystem and then
when you do that query on cfs or raw it has to go to disk, the rigth
thing to do (should do) is give all that memory to oracle. then you will
see the difference

again, it's not abug, don't think it's slow, just do the right thing.
and look in archives for a pointer to the discussions

Wim

On Fri, Jul 16, 2004 at 09:39:33AM -0700, Varghese Abraham wrote:
> 
> Hi All,
>  we are using Red Hat 2.1 Kernel e38 along with MSA 1000.
> ocfs version being used is
> 
> $ rpm -qa | grep ocfs
> ocfs-tools-1.0.10-1
> ocfs-2.4.9-e-enterprise-1.0.12-1
> ocfs-support-1.0.10-1
>  
> 
> Database Version is 9.2.0.5
> 
> 
> However we find that the performance of the database on OCFS is too slow. even a select count(1) from all_tables takes like a while to complete.
> 
> We initially assumed RAC is the problem area.  ( Because with both nodes enabled we had terrible performance)
> 
> Hence we stopped one of the RAC Databases to test out the performance.
> However even with one node the performance is real bad.
> 
>  
> 
> Any pointers on how to debug this problem.
> 
> 
> R'gds
> Varghese Abraham.
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