RE: [Cs-club] Virtual Memory

["Jonathan Steinert" <hachi@kuiki.net>]

Got this message from tyler, thought you guys might like the answer too.

> -----Original Message-----
> From: Mr Plate [mailto:plat@dillfrog.com]
> Sent: Thursday, September 19, 2002 5:09 PM
> To: hachi@kuiki.net
> Subject: Re: [Cs-club] Virtual Memory
>
>
> Hey Jon,
>
> How does the location of the swap partition(s) on your hard disk make a
> difference? That is, when is it better to put it toward the
> center or outer
> ring of the disk? Or somewhere in between?

All of this depends on what kind of performance you are looking for in your
swap space versus other partitions on the drive. If you expect to be
swapping large pages of ram in and out repeatedly, as the case would be when
doing major data processing, then you would want to place the swap space on
the outer tracks of a disk. Otherwise, in the case of most of my machines, I
mostly expect to swap out old programs and largly useless pieces of data, so
I place the swap space on what I believe to be the inner tracks of the disk.

There is a small problem with IDE disk drives these days, with the use of
LBA (Logical Block Addressing) you can't really be sure which cylinder
numbers are actually on the inner or outer portions of a disk. In order to
benchmark the disk (and thus find the fastest or slowest portions of a disk
you will need to use a utility such as bonnie(8) or bonnie++(8) and map
areas of your disk to determine where your cylinder extremeties are.

There is a ton of information located in the "Multi Disk System Tuning"
howto in the LDP, one of the many places you can see it is at
http://www.tldp.org/HOWTO/Multi-Disk-HOWTO.html

--hachi

>
> Tyler
>
> On Thursday 19 September 2002 12:57pm, you wrote:
> > > -----Original Message-----
> > > From: cs-club-admin@lists.uwosh.edu
> > > [mailto:cs-club-admin@lists.uwosh.edu] On Behalf Of Brian Behling
> > > Sent: Thursday, September 19, 2002 12:48 PM
> > > To: cs-club@list.acs.uwosh.edu
> > > Subject: [Cs-club] Virtual Memory
> > >
> > >
> > > Does any one know if Linux makes use of virtual memory?
> >
> > That would be your swapspace, while it's not necessary it is a very good
> > idea. Linux likes to swap out old pages of ram and use your ram for
> > higher priority things (like buffer space)
> >
> > On i386 using your usual partition tables a type 82 partition would be
> > your swap space, you can check for this information using cfdisk(8) or
> > fdisk(8). Swap spaces can be turned on manually using the swapon(8)
> > command in linux.
> >
> > See the manpage for mkswap(8) for more information.
> >
> > --hachi