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

  • From: Mladen Gogala <gogala@xxxxxxxxxxxxx>
  • To: peter.sharman@xxxxxxxxxx
  • Date: Wed, 22 Jun 2005 01:05:10 +0000

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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