Oracle FAQ | Your Portal to the Oracle Knowledge Grid |
Home -> Community -> Mailing Lists -> Oracle-L -> Re: OT: question about sizing swap for solaris
The link to the paper is:
http://www.sun.com/solutions/blueprints/1202/817-1054.pdf. As
Brian_P_MacLean has quoted.
My question is pretty easy: how does the word make sense ,if it not because
of swapping-algorithm bugs:
"A more serious problem, however, is that sizing swap to be too large can ause hard-pageout1 to occur too easily."
> Responses inline...
> Well, I haven't read the still-unreferenced paper, but absolutely there is
a
> difference between my opinion and what the paper apparently says - to be
> clearer, in my opinion: low swap size "prevents" page faults (by
triggerign
> errors, instead) only in the same sense that running out of gas "prevents"
bad
> gas mileage!
>
> My statement applies to database servers and non-database servers, alike.
Where
> I have specifically, quantitatively measured the true end-user costs of
paging
> and swapping, I have never seen them to be high, except on systems that
were
> victims of operating-systems swapping-algorithm bugs, which have
long-since
> been fixed. I *have* heard plenty of *anecdotes* about swapping and paging
> being big problems, but I have never seen these stories backed up with
hard
> data. I certainly believe it's *possible*, though - you just need to buy
less
> memory than you need, in spite of how cheap memory is. I have gathered
data on
> a different subset of systems than you have, however, so it is entirely
> possible you have seen one of those hypothetical systems with insufficient
> memory.
>
> >
> > Regards>
-- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------Received on Wed May 05 2004 - 00:28:59 CDT