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

 >
>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 

this is not true for a real CFS. A proxy-cfs or nfs
exhibits the characteristics you fear, but not a
fully symmetric, concurrent read:write CFS. Demand
paging is nothing more than the internals of mmap 
which in turn is really nothing more than an IO.
Oh, with one exception, it is entirely 100% read only
(a major text fault that is).  That concern is a 
red herring. Binaries execute just fine from a CFS.



>$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
>
>
>
--
http://www.freelists.org/webpage/oracle-l

Other related posts: