Re: Excessive Memory Loss on Sun Solaris using Oracle 805

Bob Pombrio wrote:
>
> On Thu, 07 Sep 2000 19:25:18 +0800, Connor McDonald
> <connor_mcdonald_at_yahoo.com> wrote:
>
> <snip>
> >Mounting your database file systems as forcedirectio may avoid the
> >"problem" and gives many other benefits as well..
>
> Such as? I am running 8.1.5 on Solaris 2.6 and I am not aware of the
> 'forcedirectio' setting.
>
> Tell me that this man isn't a GENIUS!!!
>
> The George Carlin Theory:
> "The most unfair thing about life is the way it ends. I mean, life is
> tough. It takes up a lot of your time. What do you get at the end of it?
> A Death. What's that, a bonus? I think the life cycle is all backwards.
> You should die first, get it out of the way. Then you live in an old age
> home. You get kicked out when you're too young, you get a gold watch,
> you go to work. You work forty years until you're young enough to enjoy
> your retirement. You do drugs, alcohol, you party, you get ready for high
> school. You go to grade school, you become a kid, you play, you have no
> responsibilities, you become a little baby, you go back into the womb,
> you spend your last nine months floating, and . . . . . .you finish off
> as an orgasm."
>
> George Carlin

forcedirectio basically avoids using the unix buffer cache for your file systems. You could call it a "first step" towards using raw systems without the 'hassle'.

(Assuming everything is file system based), you get mega benefit from putting your redo logs via forcedirectio, since the writes to these are in smaller quanta (typically 512bytes) than the file system would prefer (typically 8k).

With datafiles as well, the OS has to flush its file sys cache out to disk which can cause things to queue up (and thus your response time to slow down).

Still - this is a compromise, and using raw or something like Veritas Quick IO is still my preference.

HTH

-- 
===========================================
Connor McDonald
http://www.oracledba.co.uk

We are born naked, wet and hungry...then things get worse