[CentOS] Good value for /proc/sys/vm/min_free_kbytes

Fri Dec 8 09:17:29 UTC 2006
Morten Torstensen <morten at mortent.org>

John R Pierce wrote:
> in our case, our production systems are a very large very complex 
> realtime oracle database running on large scale Sun enterprise hardware 
> on bigiron EMC storage, using dozens and dozens of raid10 logical 
> volumes as you do NOT want to have a single 10TB volume, sorry.   by 
> hand optimizing the tablespace layouts of the applications tables and 
> indicies, which have very specific access patterns, we can get double 
> the throughput of the blind 'just stripe the universe' approach.   Since 

Oh you would not have a single 10TB volume of course: and it is still a 
little quaint to hand optimize tablespaces. That is something we did in 
the 90s.  Our own tests on multi-TB databases and modern SAN systems, 
the shotgun approach beat hand optimization every time. And we are 
talking about people with dozens of years with SQL optimization behind 
them. Intelligent I/O prefetch adaption, intelligent and dynamic access 
plans... the world of performance in the RDBM world is changing and old 
rules for performance are changing with it.


//Morten Torstensen
//Email: morten at mortent.org
//IM: Cartoon at jabber.no morten.torstensen at gmail.com

And if it turns out that there is a God, I don't believe that he is evil.
The worst that can be said is that he's an underachiever.