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Re: Cache & RAM disks?

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John Weinshel
 
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Default Re: Cache & RAM disks? - 07-31-2003 , 04:19 PM






Mike D asks:

"or is the built-incacheing in OSX good enough."

....and I'm wondering, Good enough for what?

There have been reports have better performance with RAM discs (although I'm
not sure how you'd set one up on X), but I'd be surprised if you saw that
much gain in a 6-100 MB system. Maybe. You're going to throw it all away
anyway when you host FMU from the same box.

FMS will not take advantage of any more RAM allocated to it, and you do not
want it to; in fact, you want to optimize that setting to get it as low as
possible and still maintain a 95% hit rate. The reason is that more memory
means more memory has to be polled for every operation, slowing performance.
For a smaller system such as you are describing, you will probably end up
with a smaller, not larger cache.

As for 'why FMServer should need to touch the disc at all', you'd have to
take that up with the FMI engineers. That's just the way they built it.

--
John Weinshel
Datagrace
Vashon Island, WA
(206) 463-1634
Associate Member, Filemaker Solutions Alliance


"Mike D" <mdNOSPAM (AT) xochiNOSPAM (DOT) com.invalid> wrote

Quote:
My database has a working set of about 60MB - 100MB. Unfortunately,
FMServer ordains that 40MB is the maximum reasonable cache size, which
is just plain silly since my Mac OS X machine has a gig of RAM.
Basically, I don't see any reason why FMServer should need to touch the
disc at all (except occasionally to flush saves).

Questions:

(1) Is there any way to hack that 40MB number higher?

(2) Does running the Database from a RAM disk help (assuming I'm willing
to risk data loss on power failure, which I am), or is the built-in
cacheing in OSX good enough. I've heard conflicting stories about RAM
disks under OSX.

--
To send email, remove the invalid and nospams.



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