[Tfug] Re: using swap file

[Tom Rini]

On Mon, Oct 31, 2005 at 05:04:08PM -0700, Robert Hunter wrote:
> Yes.  No.  Maybe. :-)
> 
> Having the swap file on a second drive is good, inasmuch as
> parallelizing disk i/o over multiple drives is a good thing.  For
> example, this is the strategy of RAID-0.
> 
> Using a slower drive than your first drive is obviously not optimal,
> but is it going to help or hinder you?  That probably depends on the
> speed difference of the two drives and how much your system is paging.
>  My guess is that as long as your second drive is not incredibly
> slower that it should be OK to use it.  On the other hand, if your
> system is paging excessively, then you will suffer accordingly, and
> you probably need more physical memory anyway.

It'll also depend on (IDE) bus layout.  Regular old non-SATA (now called
PATA) IDE will probably be a loss if you have to put the drive at hdb,
but a wash at hdc.

As Robert says, if you're paging excessively, you really need more RAM,
regardless.  I'd go farther and say if you're looking for a minor perf
win, adding more RAM will probably help you a lot more than lots of
swap, unless you've got big tasks that're idle a lot and you can afford
to swap them in/out.

-- 
Tom Rini
http://gate.crashing.org/~trini/