RE: 64 node Oracle RAC Cluster (The reality of...)

  • From: "Pete Sharman" <peter.sharman@xxxxxxxxxx>
  • To: "gogala@xxxxxxxxxxxxx" <gogala@xxxxxxxxxxxxx>
  • Date: Wed, 22 Jun 2005 11:48:53 +1000

Are you specifically talking about OCFS or the CFS that is provided by the OS?  
You know a lot more about the OS level stuff than I do (not that it would be 
hard to do that!)  I'm not sure if these are generic OS concerns you have or 
ones specifically aimed at OCFS (which is another thing I don't know much 
about!)

 
Pete
 
"Controlling developers is like herding cats."
Kevin Loney, Oracle DBA Handbook
 
"Oh no, it's not.  It's much harder than that!"
Bruce Pihlamae, long-term Oracle DBA

-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On 
Behalf Of Mladen Gogala
Sent: Wednesday, 22 June 2005 11:05 AM
To: peter.sharman@xxxxxxxxxx
Cc: kevinc@xxxxxxxxxxxxx; mwf@xxxxxxxx; Rich.Jesse@xxxxxxxxxxxxxxxxx; 
oracle-l@xxxxxxxxxxxxx; Peter Ross Sharman
Subject: Re: 64 node Oracle RAC Cluster (The reality of...)


On 06/21/2005 08:42:50 PM, Pete Sharman wrote:
>
> Seriously, where a CFS is supported by the OS, why would you do anything else 
> for the ORACLE_HOME?
>
>
> Pete


Because CFS might not be the best fit for a myriad of small files that need to 
be paged
into the memory quickly. CFS may not support anything but direct I/O, therefore 
not caching
$ORACLE_HOME/bin/oracle and shared libraries on $ORACLE_HOME/lib, which means 
that almost
all page faults will be hard faults. On the other hand, if CFS does cache files 
as is the case
with UFS by SUN Microsystems, it needs the same type of mechanism to 
synchronize the caches
across the nodes as are the ones used by oracle. That might perform well only 
if background_dump_dest,
user_dump_dest and core_dump_dest are not on the same global file system. Also, 
resist temptation
to put archive destinations on CFS. Putting it on normal FS and then sharing it 
over public connection
by NFS is much faster then by putting it on CFS.
--
Mladen Gogala
Oracle DBA


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